Fixing HHVM compatibility of the proxy generator when generating proxy classes with methods using `callable`
Fixing HHVM compatibility of the proxy generator when generating proxy classes with methods using `callable`

Also splitting logic into smaller, simpler methods

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