Fix for bug 92593: Changing a bugs product will no longer remove the votes from that bug unless the number of votes for a given user is beyond what is allowed per-bug on the new product.  Only the per-bug vote count is checked.  If the user is beyond the per-product vote limit for the new product, it is left alone, on the theory that it's better to preserve the votes on the bug.  The user will be forced to reduce their votes to fit the product limit the next time they try to vote on something.
Patch by Jake Steenhagen <jake@acutex.net>
r= justdave@syndicomm.com