Fixed a problem with serializer.
Fixed a problem with serializer.

With this commit, cache driver uses igbinary as default serializer. Other serializer options fails with ClassMetadata like object data.

racheldomingo/common,gencer/common,doctrine/common,wuxu92/common,Ocramius/common,Majkl578/doctrine-common,sachintaware/common,ptlis/common,guiwoda/common,TomasVotruba/common,dunglas/common