Clear, Site meta, Responsive style, Upgrader

* Clear: added patch to clear the entire site (wipe!)
* Site meta; added correct caching
* Responsive style is no longer added when user is in backend screen
* After a full wipe of all data, switching theme will re-import data
from resource file
* Upgrader; added ability to upgrade an entire post
* Upgrader; added ability (patch) to upgrade an entire site (all posts)
* Upgrader; fixed issue that turned all widgets into text widgets