Merge branch 'release/5'
Bumps version numbers for development version. Refs #10.
Uses GCD for thread safety. Refs #11.
Figures out time limits. Refs #11.
Builds different date formatters for the time limits. Refs #11.
Finishes date formatters. Refs #11.
Documents task in changes log. Refs #11.
Merge branch 'feature/t11_improve_date_formatting'
Avoids iOS6 specific formatter bug. Refs #11.

See http://stackoverflow.com/a/20096452/172690 for more information.
Bumps version number for v5.2 release. Refs #12.
Merge branch 'release/5.2' into stable