LUN-1033: added folder type field.
Added site field for folder.
* merged all add folder forms into one.
* moved folder duplication form validation in model validation
* added restrictions for site folders
* some pep8 & pylint
* removed the make_folder view and added new one that uses
	django's add view
* site for site folders can be changed only on root folders
* the site for root site folders are set(on save) for all
	subfolders
Added folder type display name in directory-listing template.
Merge remote-tracking branch 'origin/master_pbs' into LUN-1033

Conflicts:
	test_settings.py
Merge remote-tracking branch 'origin/master_pbs' into LUN-1033
New tests - unfinished. New folder type permission rules.
Added some more permissions tests
Added tests for moving files based on filer type permissions layer
Changed file/folder manager to support chainable querysets
Move/copy actions now excludes core folders from destinations
Refactored admin tests.
* Core folder files => readonly + no submission in view;
* Restricted permissions in core folders for 'single file'
	move to clipboard;
* Added file name validation on move action;
* Added restricted on extracting archive files;
* Files with name confliction on 'move from clipboard' will not get
	deleted anymore;
* Some folder functions/buttons will no loger appear in template
	if folder is core folder ;
* Code refactoring in admin tests;
* Added some helper functions for admin tests;
stupid 'self' instead of awesome 'TestCase'
*extracting archives no longer available in: core or unfiled files;
*archive zip validation detects malformed files;
* added tests for folder save functionality
Removed FILER_ALLOW_REGULAR_USERS_TO_ADD_ROOT_FOLDERS since there
	is no more functionality for it.
* impoved performance on find_all_duplicates method.
* find_duplicates method returns now queryset instead of list
Removed folder permission model and all its logic.
Added django-cms-roles as a dependency for django-filer.
THe permission management will be build on top of cmsroles.
SitFolder: viewable by users that have access on the folder's site
* moved views methods in the specific model admins;
* added new admin tools to detect if user has permissions
	for specific actions
* added site filtering based on user roles over sites
* action checkboxes will not be available for core files
	and folders;
* actions will not be available when doing searches
* replaced all permission logic
* left all disabled actions commented and mostly unchanged;
	these will need to be changed if they will be
	enabled again
Removed unused tests for old permissions.