Added mutexes for initialization of static collections inside of ActiveRecord.
Updated assembly versions to 2.2.1
Added missing keywords & description to the post entity.
Merge remote-tracking branch 'origin/2.2.1'
Merge branch 'master' of github.com:PiranhaCMS/Piranha
Fix for attribute routing in MVC 5.1
Merge branch 'attribute-routing' of https://github.com/bapti/Piranha into bapti-attribute-routing
Merge branch 'bapti-attribute-routing'
Merge branch 'master' of github.com:PiranhaCMS/Piranha