paster_commands: remove unused imports

Remove some unused imports, using 'autoflake' followed by manual redacting.
find kallithea/lib/paster_commands/ -name "*.py" \
| xargs autoflake --remove-all-unused-imports -i

This same command could be applied gradually throughout the code base as
areas are touched. Since autoflake may be too greedy in special cases, it is
more difficult to do a big-bang action over all code.

gearbox: if a config file is specified, store it in the command instance so it is available without tg

This will prevent a plain 'gearbox make-rcext -c kallithea.ini' from crashing in

here = config['here']

Note:
kallithea.CONFIG serves a very similar purpose.

Modified by Mads Kiilerich.

rcext: this command actually *does* require a config file ... but doesn't require db configuration

'gearbox make-rcext' would fail when trying to do config['here'] without
initializing the configuration.

The command would work if we gave it a whole db session, but it is more correct
to only require the configuration if that is all it need. The command will
however still fail, as the configuration isn't passed on to tg.config .

backend: replace Pylons with TurboGears2

Replace the no-longer-supported Pylons application framework by TurboGears2
which is largely compatible/similar to Pylons.
Some interesting history is described at:
https://en.wikipedia.org/wiki/TurboGears

Changes by Dominik Ruf:
- fix sql config in test.ini

Changes by Thomas De Schampheleire:
- set-up of test suite
- tests: 'fix' repo archival test failure
Between Pylons and TurboGears2, there seems to be a small difference in the
headers sent for repository archive files, related to character encoding.
It is assumed that this difference is not important, and that the test
should just align with reality.
- remove need to import helpers/app_globals in lib
TurboGears2 by default expects helpers and app_globals to be available
in lib. For this reason kallithea/lib/__init__.py was originally changed
to include those files. However, this triggered several types of
circular import problems. If module A imported something from lib (e.g.
lib.annotate), and lib.helpers imported (possibly indirectly) module A,
then there was a circular import. Fix this by overruling the relevant
method of tg AppConfig, which is also hinted in the TurboGears2 code.
Hereby, the include of something from lib does not automatically import
helpers, greatly reducing the chances of circular import problems.
- make sure HTTP error '400' uses the custom error pages
TurboGears2 does not by default handle HTTP status code
'400 (Bad Request)' via the custom error page handling, causing a
standard non-styled error page.
- disable transaction manager
Kallithea currently handles its own transactions and does not need the
TurboGears2 transaction manager. However, TurboGears2 tries to enable it
by default and fails, throwing an error during application initialization.
The error itself seemed to be harmless for normal application functioning,
but was nevertheless confusing.
- add backlash as required dependency: backlash is meant as the WebError
replacement in TurboGears2 (originally WebError is part of Pylons). When
debug==true, it provides an interactive debugger in the browser. When
debug==false, backlash is necessary to show backtraces on the console.
- misc fixes

gearbox: replace paster with something TurboGears2-ish that still works with the Pylons stack

This is a step towards moving away from the Pylons stack to TurboGears2, but
still independent of it.


Some notes from the porting - it could perhaps be the missing(?) documentation
for migrating from paster to gearbox:

Note: 'gearbox' without parameters will crash - specify '-h' to get started
testing.

Replace paster
summary = 'yada yada'
with the first line of the docstring of the Command class ... or override
get_description.

Note: All newlines in the docstring will be collapsed and mangle the long help
text.

Grouping of commands is not possible. Standard commands (for development) can't
be customized under the same name or hidden. (Like for paster, the conceptual
model also assumes that the sub-command naming is namespaced so commands from
other packages won't conflict.)

The usage help is fully automated from the declared options.

For all deprecated Commands, replace paster
hidden = True
with gearbox
deprecated = True

Note: config_file, takes_config_file, min_args and max_args are not available /
relevant.

The gearbox parser is customized by overriding get_parser - there is nothing
like paster update_parser.

Gearbox is using argparse instead of optparse ... but argparse add_argument is
mostly backwards compatible with optparse add_option.

Instead of overriding command or run as in paster, override take_action in
gearbox. The parsed arguments are passed to take_action, not available on the
command instance.

Paster BadCommand is not available and must be handled manually, terminating
with sys.exit(1).

There is no standard make-config command in gearbox.

Paster appinstall has been replaced by the somewhat different setup_app module
in gearbox. There is still no clean way to pass parameters to SetupAppCommand
and it relies on websetup and other apparently unnecessary complexity. Instead,
implement setup-db from scratch.


Minor change by Thomas De Schampheleire: add gearbox logging configuration.
Because we use logging.config.fileConfig(.inifile) during gearbox command
execution, the logging settings need to be correct and contain a block for
gearbox logging itself. Otherwise, errors in command processing are not even
visible and the command exits silently.

tg: minimize future diff by some mocking and replacing some pylons imports with tg

No actual tg dependency yet, just a temporary hack faking tg as an alias for
pylons.

Based on work by Alessandro Molina.

paster: drop insertion of root path in sys.path

Most paster commands inserted the root of the kallithea app in sys.path ... but
only after loading all the Kallithea modules. That seems a bit pointless.

paster: split paster specifics out of kallithea.lib.utils

BasePasterCommand and ask_ok are only useful in a Paster/command-line
context, and can thus be removed from the already overly cluttered main
utils module.

(The new common.py has been added to Mercurial as a copy of utils.py,
preserving its file history, but creating a somewhat bewildering diff.)

cleanup: get rid of dn as shortcut for os.path.dirname

We keep 'dirname' as shortcut despite having removed the 'join' shortcut:
* the name is less ambiguous than 'join'.
* dirname is often applied multiple times - spelling it out would be too
verbose.

remove vestiges of Python 2.5 support

We only support Python 2.6 and 2.7; hence we do not need to import
with-statement support from __future__.

rcextensions: cleanup of code and documentation

More cleanup is needed - this is just to clarify what it currently does.

Correct licensing information in individual files.

The top-level license file is now LICENSE.md.

Also, in various places where there should have been joint copyright holders
listed, a single copyright holder was listed. It does not appear easy to add
a link to a large list of copyright holders in these places, so it simply
refers to the fact that various authors hold copyright.

In future, if an easy method is discovered to link to a list from those
places, we should do so.

Finally, text is added to LICENSE.md to point to where the full list of
copyright holders is, and that Kallithea as a whole is GPLv3'd.

Second step in two-part process to rename directories.
This is the actual directory rename.