A few more RC1 prep fixes

- fix select boxes with size not having auto heights and then only showing 1 option
- improve a bit the site_action value in context if dispatcher does not have the action
- two errors in the BB site log.  
  -  BB has a 1 in 1000 chance call to waste spammer time.  Problem was it tried to run optimize on a table, which is mysql only.  I've added the check to the other mysql specific calls BB makes to call the right functions.  Never saw the error before due to the slim chance the function gets called.
  -  An old bug with the whitelist arrays being placed against the wrong keys.  Not sure why it never showed up before (undefined index USER_AGENT, whitelist.inc.php line 19)  so I hope this takes care of that.