infinite loop fix

[wickedOne]

fixes an infinite loop which would occur when an interface extends an improperly named interface ending with Exception as there's no T_EXCEPTION token and the only way to sniff the correct naming of an exception is to detect the classname when it's extending an exception.

nevertheless the incorrect naming of the extended class should raise an error in the extended class itself rather than in the class which is extending it

fixes #171

[mmoll]

@wickedOne Could you add a test?

[wickedOne]

no actually not. as described above, an error is thrown regardless...

nevertheless the incorrect naming of the extended class should raise an error in the extended class itself rather than in the class which is extending it.

[mmoll]

@wickedOne Next time I'll run the coverage report before asking for that, sorry for the noise :bowing_man:.

[djoos]

Thanks for your contribution @wickedOne and the review @mmoll!