PGA3 Query Builder Files

I added a few things to CVS.

* Adding QBJoin.cpp/QBJoin.h (this is a join form for the query builder,
subject to change as features develop).
* Events.cpp: Appended the QueryBuilder to the main form with the new
"frames" construct. Also, took references out of the "frmMain.h" to increase
compile time.
* Added a resource to pgadmin3.cpp ("frmQBJoin.xrc").
* I added the exact same resource into the GTK directory, but I don't have
GTK, so i have no idea if it will work (I assume it will).
* Added a new folder under "UI" in the PGAdmin3 Project file called "Query
Builder" and added all .cpp files to it (to help organization).
* Cleaned, rebuilt and tested.
* Drag and drop functionality is a *little* sensitive, so sometimes double
clicks might be interpreted as drag/drop. This will be fixed in the next
update.

-Keith