* add get id to retrieve filter id
* service getFilter && getFilterbyId returns now new Filter instead of filter ids
* add remove filter method
* adapt new service getFilter behaviour
* store since date as pattern instead of actual date string
* add remove filter to filter list controller
* move date pattern handling into Filter
* add getSinceDate to retrieve a date without seconds for displaying in the ui
* add getSinceDateIso to retrieve date ISO string for github calls
* refactor to use getFilter right after change
* use getter instead direct access to filter options object
* add remove filter handling
* Filter now takes the id as argument and fetches the options by its own
* rename getFilter to getAllFilter
* remove getAllComments from Filter because CommentCollector takes of this