spearmint: If ERR_DROP while switching gamedir, change back to last one
spearmint: Only error once for missing default.cfg

Use Com_Error so client can try to load previous game instead of exiting.
spearmint: Change title of pk3 mismatch dialog
spearmint: Don't refresh master addresses when ever get a info request

Causes server to hang the first time if not sending heartbeats to masters.