Clean up models with an micin for ACE objects.
Refactor ACL code to seperate django app.
Merge branch 'master' into new-acl-system

Conflicts:
	timesketch/apps/sketch/models.py
	timesketch/apps/sketch/tests.py
Merge branch 'master' into new-acl-system
Fix for model field owner rename
Move tests to the new acl app
Add get_named_views helper function
Fix pylint reported errors
Better comment and docstrings
Fixing comments from code review