Remove useless persistMatchSettings and handle some which weren't handled
Fixing issues in rP25077
Everyone make sure to delete savegames, saved campaigns an most importantly your matchsettings.json's (regular alpha players won't notice since there is a version check, but if you already have your stuff at A26/svn, you will have some issues)
Reported By: elexis
Comments By: wraitii, Freagarach
Differential Revision: D4240