Added initial interface for storage engines
Continued rejigging and simpifying (dead commit)

includes/admin.php:
- Starting writing new resync function that will be called sync to faceboook
- Created a function to specifically resync the list of galleries with facebook
includes/class.fbsyncStoreNextgen.php, includes/class.fbsyncStoreWordpess.php
- Started creating classes for both the standard wordpress storage and Nextgen
  gallery storage.