TryGhost/Ghost — pull request #3230 by jaswilli (2014-07-09 22:20:16+00:00)
Title: Fix active theme selector.  Add validation to API.

Closes #3226
* Remove dependent property from the computed content property
that is used to build the active theme selector.
* Add validation to the Settings model so that it rejects
attempts to set an activeTheme that is not installed.