Remove hardcoded types

[Laar]

The types used as function arguments are defined in Spec/Parsing.hs. This hardcoded translation is far to brittle as it will break when opengl-api defines a new (and used) type or one of the untranslated types is used again. Furthermore such a translation is an unnecessary restriction on the output.

So this translation should be moved to its own configuration file, which could be very simple. Further additions could include detection of undefined types and creating a default translation file.

[Laar]

As a temporary measure I've improved the error message of the failing function in 2ec00aa.