Initial filters work

Contains models for 
* for creating filters
* associating em with filter rules
* binding filters with repos
* Initial Implementation for content view definition "publish" operation (works only for package name regex filter)

Controller
* API controller for filter create/list/show//delete

Cli
* cli commands to create/list/show/delete based of https://fedorahosted.org/katello/wiki/ContentViewFilters  (Cli general usage section other calls on way)

Tests
* only cli based ones for now, working on other tests based of 
https://pad-katello.rhcloud.com/p/parthas