The function eolian_implement_information_get was returning strings for
the class and the function. It was written in this way at the beginning
because it was not needed to verify the correctness of the class and
the function.
Now that we have the namespace feature, this function must check it,
meaning that the class and the function are now known.
So we can return them instead of returning the strings.
The generators had to find the class from the classname. It is no more
needed.
The C++ generator has been adapted to this new API.
Until now, the functions giving access to class information were taking
the class name as parameter.
Except the fact that we needed to search into a hash table for the internal
class structure, no flexibility is possible.
This change consists in modifying most of the APIs using the class name
with a new Eolian_Class type and adapt the code of the C and C++
generators accordingly.