UserGroup on UserGroup permissions implementation.
- user group can have another usergroup assigned
- it's impossible to assign usergroup on the same usergroup

implemented usergroup permissions checks.
- each user who has now explicit or inherited permissions can create usersgrous
- user is automatically an admin of that usergroup, and can manage it

Iteration on default permissions
- added user groups default
- organized global permission form, and made it common for
users, and user groups
- form improvements and intructions

consistent handling of grant/revoke of permissions widgets
- use 1 method for users and for users groups
- use common JS for ajax revoke
- cleanup code

- 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

user group: sort lists of current and available members by username

It was hard to navigate lists with 200 users in "random" (user_id?) order.

further cleanup of UsersGroup

Renaming some names ... but trying not to change API or database scheme.

"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.

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

sqlalchemy sessions cleanup in admin
Cleanup settings options

Implemented #467 Journal logs comments on changesets
- added created/updated user action to journal
- added created/updated users group action journal
- added ip adresses to most of action_log calls to track IP changes
- rewrote action_parser to simpler and more efficient solution

utils/conf
- created temporary utils2
- made config.conf for storing some configurations
- fixed some dependency import problems
- code cleanup
- rc-extensions now properly work for celery

commit less models
- models don't do any commits(with few exceptions)
- all db transactions should be handled by higher level modules like controllers, celery tasks

removed users_group controller in replace for model methods,
fixed tests

Fixed permissions for users groups, group can have create repo permission now.
Some code refactor + pep8ify

Major rewrite of auth objects. Moved parts of filling user data into user model.
Rewrote AuthUser adding access by api key.

#56 fixed relationship query behavior to speed up fetching, and
added tooltip showing group members

#56 implemented users groups editing,
fixed sqlalchemy relation function into relationship (according to 0.6)

#56 fixed found bugs, implemented adding of new group + forms+validators
fixed db schema naming