speed up when using factories: replaced str_replace with strtr
removed some code from generated factories that is not necessary anymore since dropping aop support
added @service support for singletons without analyzing constructor arguments for the singletonkey -> better speed
replaced json_encode with serialize when generating singleton keys to speed up key generation
* allowing real singletons to be marked as service
* some code cleanup so that singletonkeys don't get created unnecessarily
default values for configuration class constructor
removed unnecessary feature