Fixes #7233 - Drop Ruby 1.8.7 and revert Ruby 1.8.7 specifics

- [x] rake test passed
- [x] rails server loaded and function correctly
- [x] Ubuntu 12.04 packaging blocker issue 
- [x] drop 1.8.7 tests on Jenkins
Oh, the above note about fast_gettext means we would need ~> 1.0 here, as 1.1 has deps on fast_gettext 0.9.