Installation of python components through ctkMacroCompilePythonScript too wide

[RafaelPalomar]

ctkMacroCompilePythonScript performs an installation step which is very wide (whole directory). This makes all build files to be installed along, i.e., the CMakeFiles directory ( SystoleOS/gentoo-overlay#75).

I think ctkMacroCompilePythonScript should not have an install step. (arguably) An install step does not fit naturally in a macro labeled with Compile. Also the user (developer) knows better what should be installed and not; i.e., SlicerMacroBuioldScriptedModule.cmake is probably a better place to do the installation step. Leaving this decision to a low level macro like ctkMacroCompilePythonScript forces the installation step to be purportedly wide.

The downside is that this will mean breaking the CTK CMake API.