Change GroupMember#update_counter_cache! to use atomic incr/decr
Change GroupMember#update_counter_cache! to use atomic incr/decr

vevix/hummingbird,saintsantos/hummingbird,paladique/hummingbird,jcoady9/hummingbird,sidaga/hummingbird,wlads/hummingbird,NuckChorris/hummingbird,paladique/hummingbird,jcoady9/hummingbird,saintsantos/hummingbird,hummingbird-me/hummingbird,erengy/hummingbird,MiLk/hummingbird,vevix/hummingbird,wlads/hummingbird,xhocquet/hummingbird,Snitzle/hummingbird,paladique/hummingbird,wlads/hummingbird,qgustavor/hummingbird,vevix/hummingbird,jcoady9/hummingbird,xhocquet/hummingbird,synthtech/hummingbird,erengy/hummingbird,NuckChorris/hummingbird,astraldragon/hummingbird,synthtech/hummingbird,cybrox/hummingbird,MiLk/hummingbird,wlads/hummingbird,sidaga/hummingbird,MiLk/hummingbird,NuckChorris/hummingbird,jcoady9/hummingbird,saintsantos/hummingbird,NuckChorris/hummingbird,vevix/hummingbird,MiLk/hummingbird,xhocquet/hummingbird,sidaga/hummingbird,paladique/hummingbird,saintsantos/hummingbird,astraldragon/hummingbird,erengy/hummingbird,xhocquet/hummingbird,xhocquet/hummingbird,sidaga/hummingbird,astraldragon/hummingbird,hummingbird-me/hummingbird,qgustavor/hummingbird,erengy/hummingbird,qgustavor/hummingbird,qgustavor/hummingbird,xhocquet/hummingbird,Snitzle/hummingbird,Snitzle/hummingbird,astraldragon/hummingbird,xhocquet/hummingbird,Snitzle/hummingbird