Added NULL checking to overloaded delete operators
Added NULL checking to overloaded delete operators

bithium/cpputest,KisImre/cpputest,dawid-aurobit/cpputest,offa/cpputest,arstrube/cpputest,KisImre/cpputest,maxilai/cpputest,offa/cpputest,dawid-aurobit/cpputest,maxilai/cpputest,Mindtribe/cpputest,asgeroverby/cpputest,PaulBussmann/cpputest,Mindtribe/cpputest,cpputest/cpputest,basvodde/cpputest,chenlianbing/cpputest,chenlianbing/cpputest,cpputest/cpputest,chenlianbing/cpputest,Andne/cpputest,basvodde/cpputest,Andne/cpputest,arstrube/cpputest,dawid-aurobit/cpputest,asgeroverby/cpputest,PaulBussmann/cpputest,KisImre/cpputest,arstrube/cpputest,KisImre/cpputest,offa/cpputest,Andne/cpputest,basvodde/cpputest,bithium/cpputest,jaeguly/cpputest,jaeguly/cpputest,devMichaelJones/cpputest,PaulBussmann/cpputest,arstrube/cpputest,Mindtribe/cpputest,devMichaelJones/cpputest,basvodde/cpputest,offa/cpputest,bithium/cpputest,maxilai/cpputest,Mindtribe/cpputest,asgeroverby/cpputest,jaeguly/cpputest,devMichaelJones/cpputest,cpputest/cpputest,maxilai/cpputest,PaulBussmann/cpputest,devMichaelJones/cpputest,dawid-aurobit/cpputest,jaeguly/cpputest,bithium/cpputest,Andne/cpputest,asgeroverby/cpputest,cpputest/cpputest,chenlianbing/cpputest