LTS-165 - Foreigner, and a number of fixes and additional paranoid models required by same.

The reason for inspiring fear in the additional models, in addition to the benefits of soft delete, is that it turns out that
anything north of a paranoid model in the hierarchy of models that has :dependent => :destroy over that paranoid model
 ALSO needs to be paranoid, or else unpleasantness arises when you try to delete something higher up the chain, and its
dependents soft-delete, and the foreign key constraint prevents soft-deletion and rolls the whole thing back.
Added details of paranoia-related model hierarchy constraints to DEV_NOTES.md
LTSINSCRIP-160 - Established MtM relationship between users and libraries for permissions.  Also includes libraries association, which represents which libraries the User has UserTypes for.
WIP cancan
STILL WIP - CanCan.  Bulletin boards are probably close to functionally covered, reservations will need more work.
Paranoid update - pointing at commit in primary github, rather than personal github of Harvard developer;
More CanCan work.  Auth is starting to come together.