Birthday thread 2.6

Birthday thread v2.6 changes:

Added Secondary user group ID to options page.

Birthday thread v2.5 changes:

Improved error handling if options not set.

Birthday thread v2.4 changes:

Added Custom user field to Options page.

Birthday thread v2.3 changes:

Updated PHP code so that 'setIsAutomated' code is correctly placed.

Birthday thread v2.2 changes:

Now using entity manager to update ThreadWatch data.

Birthday thread v2.1 changes:

Now using finder for performing database queries.

Birthday thread v2.0 changes:

Added code to prevent birthday threads being created for banned members.

Birthday thread v1.9 changes:

Updated options page. Now uses easier to use Destination forum selector.

Birthday thread v1.8 changes:

Added user group permissions to make it easier to select with group will receive a birthday thread.

Birthday thread v1.7 changes:

Add-on now properly updates thread watch so thread starter will properly get alerts when the new member replies.