Fixes #1117214 by Dave Cohen,james.williams: fixes a PHP warning on account form, and probably fixes a bigger problem in which mappings to facebook accounts are accidentally deleted.

by Dave Cohen: several changes - initialize FB API in hook_custom_theme, earlier in Drupal bootstrap so that it can be used in menu callbacks.  Add method param to fb_graph(). fb_graph_load for menu wildcards.  Cleaned out some obsolete code.

fb_permission_access_perms is intended to be a drupal menu access callback that ensures certain perms are granted.  Not perfect - under development.

by Dave Cohen: new hook after setting props, gives third party modules a chance to set additional attributes of an app.

Supports page paths for both liked and not-liked pages.  AKA fan gating.

fixes: #1166272 by Dave Cohen, John Klehm: support for facebooks oauth 2.  Mostly an upgrade of fixes from 6.x branch.

more verbose exception handler.
menu loader for %fbu.