Forgot to move code for zoomin/zoomout into AM_Responder

git-svn-id: http://mancubus.net/svn/hosted/eternity/trunk@2397 86ba831e-150c-0410-ab35-e06eaae15ed9
* Started refactoring G_KeyResponder and responder functions to eliminate action_ vars and use more vanilla-like logic.
* Minor cleanup in g_game

git-svn-id: http://mancubus.net/svn/hosted/eternity/trunk@2398 86ba831e-150c-0410-ab35-e06eaae15ed9