Add authorization for channels; initial implementation is such that only administrators may delete channels. (refs #131, #154)
Don't render delete button unless channel metadata contains trueish destroyable flage.
Introduce channel ownership; delete button only displayed for destroyable channels (non-primary, owned, or all except primary channel if you're an admin).
Channels now need a user.
Remove obsolete additional attribute for channel JSON.
Add users_controller and set as show/index resource in routes.
fix abilities for channel ownership
Better user handling; better initialization callbacks.
Increase capybara wait time to 10s for locating .chat-input.
Slight refactoring; added comments about what is going on. :)
Use #create! to ensure channel creation fails noisily if it doesn't validate correctly; ensure the primary channel is assigned to the primary user.
Merge pull request #223 from mjtko/kandan-131

Add ownership to channels and associated enhancements