Updated!
Version 1.8.4
http://pastebin.com/9B0hWVCC
Changes are listed on the top of the source code.
The biggest change is that
the instances now use DBI.
Reading Qglobals now by using DBI to 100% guarantee seeing the values qglobals for credit balance, if instance is created, list of invited players etc. Still don't know why randomly 5% chance for zones to not refresh memory what the qglobals are. DBI fixes this, possibly at the cost of performance (so far haven't noticed any performance hit). The new sub for reading qglobals is small and simple, returns the value of the qglobal. Did a find/replace on all the $qglobal{$variable} with the new sub fuction name.
Writing to the Qglobals table works the same way as before with setglobal command.
Fixed minor bug that players needed to be in the same public zone to invite each other into raid or guild instances. Now the leader can invite any player that is in any zone public or instance etc.
Also can now remove a player from the invite even if the player is in a different zone. When removing a player, it will zone them to the public version of the current zone the player is in if they are in the same zone name as the instance they were removed from. Else if they are in a completely different zone, then they will get the message but won't be teleported to the public version since there is no need. You can re-invite players after they have been removed/banned from the instance.
Players without guild can no longer create a guild instance with id of -1 and it will tell them that they have no guild if trying to create.
Enjoy!