Warn if cache directory cannot be created
Warn if cache directory cannot be created

closes #1161

floverdevel/composer,milleruk/composer,Teino1978-Corp/Teino1978-Corp-composer,bd808/composer,SpacePossum/composer,00F100/composer,dzuelke/composer,nevvermind/composer,cgvarela/composer,johnstevenson/composer,oligriffiths/composer,dymissy/composer,curry684/composer,JBleijenberg/composer,marcuschia/composer,myPublicGit/composer,blacksun/composer,balbuf/composer,stof/composer,ncusoho/composer,melvis01/composer,mikicaivosevic/composer,kidaa/composer,davidolrik/composer,yaman-jain/composer,cesarmarinhorj/composer,yinhe007/composer,gsdevme/composer,pierredup/composer,remicollet/composer,fh/composer,jtanjung/composer,gencer/composer,druid628/composer,Seldaek/composer,javihgil/composer,hirak/composer,staabm/composer,guillaumelecerf/composer,theiven70/composer,olvlvl/composer,fabpot/composer,thetaxman/composer,sroze/composer,Risyandi/composer,AndBicScadMedia/composer,stefangr/composer,Netmisa/composer,composer/composer,mrmark/composer,alcohol/composer,till/composer,localheinz/composer,zgj12306/composer,ammmze/composer,erasys/composer,nicolas-grekas/composer,fabiang/composer,Danack/composer,slbmeh/composer,jreinke/composer,DiceHoldingsInc/composer,andrerom/composer,Nicofuma/composer,vdm-io/composer,yched/composer,phansys/composer,nater1067/composer,MoT3rror/composer,Soullivaneuh/composer,naderman/composer,brighten01/composer,GodLesZ/composer