CC-5709: Airtime Analyzer

* File import via the Add Media page now works!
* Reworked StoredFile::copyFileToStor() because it's still needed.
* Reworked the way file paths are reported in airtime_analyzer
  and in the RESTful media API
Merge branch 'cc-5709-airtime-analyzer' of github.com:sourcefabric/Airtime into cc-5709-airtime-analyzer

Conflicts:
	airtime_mvc/application/modules/rest/controllers/MediaController.php