Add CAS methods to Null memcache
Add CAS methods to Null memcache

This prevents breaking ownCloud completely when memcache is not enabled
and the locking code is triggered

endsguy/server,andreas-p/nextcloud-server,pixelipo/server,sharidas/core,cernbox/core,whitekiba/server,endsguy/server,endsguy/server,sharidas/core,IljaN/core,bluelml/core,andreas-p/nextcloud-server,bluelml/core,jbicha/server,IljaN/core,xx621998xx/server,IljaN/core,andreas-p/nextcloud-server,Ardinis/server,pollopolea/core,jbicha/server,cernbox/core,endsguy/server,cernbox/core,pixelipo/server,whitekiba/server,pmattern/server,bluelml/core,sharidas/core,pollopolea/core,whitekiba/server,owncloud/core,lrytz/core,pollopolea/core,Ardinis/server,michaelletzgus/nextcloud-server,lrytz/core,lrytz/core,xx621998xx/server,nextcloud/server,jbicha/server,nextcloud/server,phil-davis/core,endsguy/server,michaelletzgus/nextcloud-server,nextcloud/server,lrytz/core,Ardinis/server,bluelml/core,Ardinis/server,sharidas/core,IljaN/core,cernbox/core,michaelletzgus/nextcloud-server,andreas-p/nextcloud-server,owncloud/core,xx621998xx/server,cernbox/core,Ardinis/server,jbicha/server,IljaN/core,pollopolea/core,sharidas/core,whitekiba/server,pixelipo/server,bluelml/core,pmattern/server,lrytz/core,owncloud/core,xx621998xx/server,xx621998xx/server,pmattern/server,pmattern/server,owncloud/core,andreas-p/nextcloud-server,jbicha/server,nextcloud/server,whitekiba/server,pixelipo/server,owncloud/core,michaelletzgus/nextcloud-server,pixelipo/server,pmattern/server,pollopolea/core