py3: officially support Python 3

All tests pass and no known regressions.

ssh: add documentation of SSH support

Based on work by Ilya Beda <ir4y.ix@gmail.com> on
https://bitbucket.org/ir4y/rhodecode/commits/branch/ssh_server_support , also
heavily modified by Mads Kiilerich and Thomas De Schampheleire.

Text related to the case where the parent directory of 'authorized_keys'
does not exist or is not writable, was contributed by Bradley M. Kuhn
<bkuhn@ebb.org>.

remove references to pythonhosted.org (issue #293)

The pythonhosted service is no longer supported.
Update links to point to docs.kallithea-scm.org (which redirects to
kallithea.readthedocs.io)

While at it, fix the whoosh pythonhosted.org reference as well.

remove references to pythonhosted.org (issue #293)

The pythonhosted service is no longer supported.
Update links to point to docs.kallithea-scm.org (which redirects to
kallithea.readthedocs.io)

While at it, fix the whoosh pythonhosted.org reference as well.

db: drop RhodeCode compatibility (database rebranding etc.)

To migrate from RhodeCode, users will have to first migrate to
Kallithea 0.3.2.

docs: add documentation for setup with puppet

Incorporates feedback from Branko Majic and Søren Løvborg.

git: add option for forcing overwrite of Git hooks when remapping and rescanning the repositories. (Issue #153)

README file was updated to include some information on updating Git hooks after migrating to Kallithea.

docs: consistent spacing around headings

Start out with 2 empty lines before/after for top level, decrease for deeper
levels.

docs: cleanup of casing, markup and spacing of headings

Mostly stuff found and fixed by Søren, extracted here to separate things.

Other uses of title casing might be debatable, but here it was just a few
documentation headings that clearly were inconsistent with the majority.

README: link to readthedocs.org rather than python.org for documentation

The documentation at readthedocs.org is up-to-date with the latest revision,
while python.org shows the latest release.

docs: rework stuff

The existing docs were far from how we wanted it to be. There was so much to do
and it is not feasible to do that cleanup it in clean patches.

Instead, I took a sweep through the docs and changed what I thought could
benefit from a change: structure, examples, advices, language, markup, content,
etc.

"Users groups" is grammatically incorrect English - rename to "user groups"

- and same story with "repositories groups"

This will only change the user facing texts. Names of files, modules, functions
and variables should be changed too.

Api docs fixes
- return proper type instead of type_
- members return now also a type user or users_group

#227 Initial version of repository groups permissions system
- implemented none/read/write/admin permissions for groups
- wrote more tests for permissions, and new permissions groups
- a lot of code garden, splitted logic into proper models
- permissions on groups doesn't propagate yet to repositories
- deprecated some methods on api for managing permissions on
repositories for users, and users groups

Fixes for release 1.1.4
Docs updates

updated setup for all newest versions
EmptyChangeset can take changeset as creation param.

refactor codes and setup for python 2.5
readme update

removed egg info, update files for distutils build
updated READMES some config files

implemented gravatars into main bar.
Readme update