* (bug 16656) cleanupTitles and friends should now work in load-balanced DB environme...

* (bug 16656) cleanupTitles and friends should now work in load-balanced DB environments when $wgDBserver isn't set.
Lots of cleanup scripts are based on the FiveUpgrade class created for the 1.5 schema upgrade -- this provides a utility class designed around pulling data from a second, unbuffered connection, processing it, and stuffing it into a master connection.
Originally, both connections were created by manually instantiating the Database class. This worked as long as $wgDBserver was set, but at some point we apparently stopped setting it in our fancy-ass load-balanced environment where we're exclusively using the $wgDBservers array.
As a result, the connections used the default $wgDBserver of 'localhost' which inconveniently fails on Wikimedia's servers. ;)
Now uses the Tim-approved method of getting a new database connection -- creates a new LoadBalancer via wfGetLBFactory()->newMainLB(), then asks it for a fresh connection.