Tagging: Add tags for TPs

Fixes bug 3035
Tagging-squash: Use AJAX for adding tags to TP
Tagging: Manage TP tags in project overview

Fixes bug 3036
Tagging-squash: Use AJAX for adding tags to TP in project overview
Tagging: Use animation when showing/hiding tags
Tagging: Show tags above TPs on Project overview
Tagging: Fix bump effect in hiding/showing tags animation
Tagging: Add support for filtering project TPs using tags

Fixes but 3037
Tagging: Use Select2 in tag filtering UI

Fixes bug 3038
Tagging: Misc styling changes