Cleaned up some extra junk

Moved FB config array to functions.php;
Added check for user trying to connect to Facebook account that is
already connected to
Modify Table Creation / Error Checking

Modified SQL to create facebookconnect table;
Added Error Check for FB App ID and Secret
Updated
Cleanup

Cleaned up some code
Updated
Cleanup

Cleaned up some code.  Moved FB config array here.  Added a check
regarding multiple e107 users trying to connect to same FB account.
Modify Table Creation

Modified SQL to create facebookconnect table