Delete Add / Edit screens (Allow add/update from server only).
Stop setting a UrlRemap reset URL (not used anymore)
Make ResourcesLoader be able to delete files (as well as directories)
Big refactor to support pushing of apps via HTTP.

This removes the AppHarness' ability to updating apps by fetching from
`cordova serve`. Instead, app resources are now pushed via
HarnessServer.
Add harness-push command-line tool for pushing apps.