Fix issue #1295: Added a check to see if every group being collected had only one TA assigned to them.
Fix for issue 1295: DIsabled button if more than one TA is marking the same set of submissions.
Added check to second branch to make sure it fails for any user except for a TA.
Fix warnings generated by assert_select

Some tags are not closed properly, so the HTML parser complains when
doing assert_select in functional tests.

Tested:
- rake test:functionals
Fix i18n warning about enforcing locale

This gets rid of the warning

```
[deprecated] I18n.enforce_available_locales will default to true in the
future. If you really want to skip validation of your locale you can set
I18n.enforce_available_locales = false to avoid this message.
```

See
http://stackoverflow.com/questions/20361428/rails-i18n-validation-deprecation-warning
Merge pull request #1487 from zhangsu/fix_i18n_warning

Fix i18n warning about enforcing locale
Merged Master fixed conflict.
Added translations for French and Portuguese, also did some formatting.
Fix for issue 1485. Updated controller to include values 500 and 1000 so that it will be added to the show xx per page filter.
Merge pull request #1499 from gello88/issue-1485

Fix for #1485. Updated controller to include values 500 and 1000.
Merge pull request #1428 from ealonas/issue-1295

Fix issue #1295: Check to see if every group being collected had only one TA assigned to them.
Merge pull request #1483 from zhangsu/fix_assert_select_warnings

Fix warnings generated by assert_select.
Resolved conflict in language files/merge with master.