[ADD] Empty collection and empty element photo to the resources
[MOD] ImageLoader to use specific empty photo to collections/elements list
[ADD] empty collection view
[MOD] ItemsListFragment to use empty collection view when collection don't have elements
[MOD] Remove Hardcoded value from ItemsListFragment, ImageAdapterList, ImageLoader
[FIX] close cursor in ImageCacheDatabase
[ADD] ProgressBar to data generator
[MOD] generator to use AsyncTask
[MOD] insert query used to create new collection in generator
[ADD] ON DELETE CASCADE
[MOD] Delete collection - set flag
Merge remote-tracking branch 'origin/sprint5' into sprint7
[MOD] Delete collection on server
[FIX] Duplicated tags in collection