Feature/core python module

After this is merged, it is intended that Lidarview/Application/Ui/python/CMakeLists.txt becomes just:

include(PythonModuleInstaller) python_module_install(NAME "lidarview" FILES lidarview/init.py lidarview/applogic.py lidarview/gridAdjustmentDialog.py lidarview/kiwiviewerExporter.py lidarview/planefit.py lidarview/timer.py lidarview/aboutDialog.py lidarview/DTMFilter/init.py lidarview/DTMFilter/DTMPythonFilter_Script.py lidarview/DTMFilter/DTM.py lidarview/visualizationTools.py")

and Application/Ui/python/compile_all.py.in is deleted

Moreover, in applogic it will be possible to do:

import lidarviewcore as lvcore

Which will allow easy factorisation of code.