first step to the big video

missing:
- thumb
- refactor js code
Merge branch 'master' of https://github.com/catarse/catarse into channel-big-video
added reward policy to pundit to replace cancan
migrated rewards controller to pundit
migrated reward views to pundit
updated child process gem
removed cancan abilities for reward
removed reward abilities
Merge pull request #558 from diogob/migrate_rewards_privileges

Migrate rewards privileges to Pundit
define end_of_association_chain into updates controller [Fix #65336710]
we need to use the lambda for prevent a weird bug :S [Fix #65336710]
removed set_email and update_email from actions, they were removed eons ago.
removed unsubscribe_update and request_update also removed long ago
added protected method only_admin to make default policies simpler
added update_password to actions list
added user policy to the project
migrated users controller to pundit
removed cancan user abilities
uservoice_gadget won't need any privilege
migrated user views to pundit