Cleaning up the MATLAB module for maintainability

[jaeandersson]

Certain parts of the MATLAB module needs to be cleaned up for maintainability:

• [ ] The implementation of several helper functions are currently implemented as multiple lines with a Printf(f_wrap_m, ...) on each line. This code should be moved to the Lib/matlab directory.
• [ ] The director support code is bloated, uncommented and mostly copy-paste. It needs to be throroughtly refactored or removed, dropping director support.
• [ ] Remove matlabprepend, matlabappend. Not consistent with good coding practices.