First step in two-part process to rename directories to kallithea.
This first step is to change all references in the files where they refer
to the old directory name.

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.

auth decorators are not used anymore on __before__
- this will allow to create a whitelist of API enabled controller functions
- moved around functions with _ to beginning of the files to make it cleaner

- Manage User’s Groups: create, delete, rename, add/remove users inside.
by user group admin.
In this case, a user's group can be owned by several people thru an owner user's group.

Some refactoring of naming, permission handling logic.
- remove some code duplicity as well as inconsistent naming

stay on repo after forking and show full path to new fork

This helps not getting lost after forking.

filter out repo groups choices to only ones that you have write+ access to. Before it was read+ access and you got proper
error saying that you don't have write permissions to group to create repo in. Filtering out the read groups is less confusing for users.
ref #730

Enabled compare engine for tags
Implemented compare engine for git repositories

Implemented permissions for writing to repo
groups. Now only write access to group allows to create a repostiory
within that group

RhodeCode now has a option to explicitly set forking permissions. ref #508
- changed the way permissons on users groups behave. Now explicit set on user
is more important than permission set on users group

Refactored create fork function to use new RepoModel functions instead of old
soon-to-be-destroyed functions

- fixed issue with missing commits on some repos commands
- fixed issue with parsing commits for stats when there were only two commits

#235 forking page repo group selection
- group is selected as parent repo
- refactoring of session behavior to get more atomic operations in models