Merge in CASinoCore logic

This PR merges in all CASinoCore functonality into CASino as discussed in rbCAS/CASinoCore#18 and based on the work @dlindahl did in #18. It preserves all of CASinoCore's git history.

## ToDo
- [x] @dlindahl: Confirm the `CreateBaseModels` migration created by `rails g casino:migrate` is a practicable solution
- [ ] Merge this PR and release a new version of the CASino gem
- [ ] Merge the pending [rbcas.github.com PR](https://github.com/rbCAS/rbcas.github.com/pull/3)
- [ ] Merge the pending [casino-ldap_authenticator PR](https://github.com/rbCAS/casino-ldap_authenticator/pull/2) and release the gem
- [ ] Merge the pending [casino-activerecord_authenticator PR](https://github.com/rbCAS/casino-activerecord_authenticator/pull/4) and release the gem
- [ ] Update CASinoApp