SlipPlane::writeAllDefects

Added the function ```SlipPlane::writeAllDefects``` to write out all defect positions for a given slip plane. This is useful for plotting data.

The ```Parameter``` class also received new data members indicating this kind of statistics.

The big advantage is that due to this the code remains the same for validation cases and only the input file needs to specify if the defect positions are to be written to file or not.