[Zend-Code] Fix Code Generation for non namespace classes

ClassGenerator and ParameterGenerator had some issues with non-namespace classes.

The ClassGenerator tried to concatenate the namespace in the check if a reflectionmethod is from the same class.

The ParameterGenerator removed the first character for non-namespace classnames.
And there is a backslash missing for non-namespace classnames. As zf2 requires 5.3.3 this slash does not hurt anyone.