[MATLAB] solve all (?) remaining problems with get/set functions

- do not write set function if the variable is immutable
- call Language::*wrappers first, as these can set immutable and other properties
- do not write get/set functions if the variable is wrapped as a constant
[MATLAB] small changes for C compatibility

- removed writing of 'extern "C"' in matlab.cxx
- removed C++ headers that were never used anyway
- changed a few cast from e.g. int(bla) to (int)bla
[MATLAB] removed Python code from std_string.i

TODO code cut was for wstrings, so this probably doesn't work therefore
[MATLAB] added std_ios.i and std_iostream.i (straight copy from python)
[MATLAB] fixed problem with dynamic_cast resolution

The dynamic_cast variables were initialised outside of the LoadModule function,
which didn't compile. This was solved by writing the closing bracket of
that function in matlab.cxx (as in ruby).
[MATLAB] added more runme functions to the test-suite (and corrected one)