Fixes Issue #375

Some of the constants are iOS 7.0+ only.
Really fix uninitialized constants for ios 6 this time.
Doh! Should be setting and getting constants on UIActivityViewController, not Kernel.
Move iOS 7 constants to their own file and conditionally compile them.
Merge branch 'refs/heads/master' into fix-ios6-uiactivitycontroller

* refs/heads/master:
  Added documentation for BW::Location.enabled? and BW::Location.authorized?
  Add BW::Location.authorized? tests.
  Add the ability to determine app location authorization and not just device specific.
  Adds App::Persistence.all documentation in readme.
  Cleaner options setting and overriding. Results in cleaner looking, more readable code.
  Fix syntax of documentation of BW::Mail
  Adds BW::Persistence.all to retrieve all keys and values stored as a hash.
Fix missing end statement.
Fix osx builds.
I think I got iOS 7 only files working properly.
Merge pull request #376 from rubymotion/fix-ios6-uiactivitycontroller

Fixes Issue #375