[merge-casino-core] Miscellaneous tidying up

This fixes two outstanding issues with in the [rbCAS/CASino/merge-casino-core](https://github.com/rbCAS/CASino/tree/merge-casino-core) branch that deprecates CASinoCore.

1. Fixes `uninitialized constant CASino::TicketGrantingTicket::UserAgent`

2. Fixes Rails code reloading issue with Processor Concerns.

   Rails would fail to automatically reload Processor Concerns because of
the non-standard namespacing.

   Following some tips from http://blog.andywaite.com/2012/12/23/exploring-concerns-for-rails-4, I namespaced the Processor-specifc concerns so that Rails could automatically determine the correct load path and handle the reload.

   Git does not want to retain the rename operation while also modifying the contents so this fix has been broken into two commits so as to try and retain the commit history.