Imported some of the GPLv3'd changes from RhodeCode v2.2.5.

This imports changes between changesets 21af6c4eab3d and 6177597791c2 in
RhodeCode's original repository, including only changes to Python files and HTML.

RhodeCode clearly licensed its changes to these files under GPLv3
in their /LICENSE file, which states the following:
The Python code and integrated HTML are licensed under the GPLv3 license.

(See:
https://code.rhodecode.com/rhodecode/files/v2.2.5/LICENSE
or
http://web.archive.org/web/20140512193334/https://code.rhodecode.com/rhodecode/files/f3b123159901f15426d18e3dc395e8369f70ebe0/LICENSE
for an online copy of that LICENSE file)

Conservancy reviewed these changes and confirmed that they can be licensed as
a whole to the Kallithea project under GPLv3-only.

While some of the contents committed herein are clearly licensed
GPLv3-or-later, on the whole we must assume the are GPLv3-only, since the
statement above from RhodeCode indicates that they intend GPLv3-only as their
license, per GPLv3§14 and other relevant sections of GPLv3.

follow Python conventions for boolean values

True and False might be singletons and the "default" values for "boolean"
expressions, but "all" values in Python has a boolean value and should be
evaluated as such. Checking with 'is True' and 'is False' is thus confusing,
error prone and unnessarily complex.

If we anywhere rely and nullable boolean fields from the database layer and
don't want the null value to be treated as False then we should check
explicitly for null with 'is None'.

implements #636, lazy loading of history and authors to speed up page responsiveness.
- loading full history is not always needed, and it's very heavy operation. Now this is lazy loaded
when clicking on button

fixed issue with show at revision button. Some JS were not properly loaded due to ajaxified files view.
Removed JS code and the logic for that is in python view now. Simpler and less ugly JS callbacks

smarter calculation of showed associated changeset in file source view
- before rhodecode showed TIP changeset when initially displaing file source as description of associated commit
this can be misleading. Now smart calculate last commit of a file, and show specific commits when switching from history view

Added h.tooltip to all places that tooltip_title is used.
- improved escaping of < and > inside tooltips

fixed vcs issue with last_changeset for filenodes
- fixed incosistency for displaying revision in file browser
- fixed raw_diff for git for single file mode
- file block now uses associated changeset for both git&hg

- added branch to history list for file
- fixed some inconsistency on file page when used mixed last_changeset with current changeset

implements #308 rewrote diffs to enable displaying full diff on each file
- fixed escaping of html special chars in file editor

Implements #304
hashes in relevant places are displayed using monospaced font.

fixes issue #320.
- added mapping of commit users into rhodecode users

new files views
- compated space
- nicer gui
- code garden

cleaned up JS files in files templates.
- fixed some small issues with editing/adding git files using codemirror
- small css fixes
- separated files/dir browsing into separate template

Fixed problem with anchor link positioning when passed in ranges.
Added anchor link tooltip for code selection

changed raw action to show images instead of saying about binary file
added mimetype to binary file text

some changes for #45.
Added warning messages for browsing wrong cs/paths
Cleanup of codes

Fixes for raw_id, needed for git
Renamed hg controller to home
css html changes