Clean up Validator and Mail components

- Fixed docblocks
- Removed some unnecessary returns
Merge pull request #2426 from DriesForks/dv/clean-up-validator-folder

Clean up Validator and Mail components
Added getLocale() method to Application which returns the current locale from the config.
Merge pull request #2429 from alexdover/getlocale

Added getLocale() method to Application
Fix order.
Cast to integer on limit and offset.
Increment version.
Change Auth::guest() to call the check() method.

Instead of reimplementing the logic of the Auth::check() method, we can call and negate it. This makes it easier to change things in a Guard subclass.
Merge pull request #2439 from franzliedke/patch-12

Change Auth::guest() to call the check() method.
Fix unguarded bug.