update to boost 1.72.0 with python 3.8

[chcg]

• update to python 3.8.2
• update to boost 1.72

Intermediate steps:

• fixed some x64 compiler warnings
• fix msi build
• updated python 3.7.5 lib data
• moved extra libs into full
• python 3.7.5
• add unicode filename testfile (removed again as MSI can't handle it)
• update to python 3.7.3
• update boost to 1.70
• update to python 3.7.1 and boost 1.68
• initial try of build adaptations for python 3 support, see Move to Python 3.8 #36 on blockage, due to missing boost python3 nuget package

[chcg]

Open issue:

• there is still a problem with GILHandler::doIHaveTheGIL()
• unicode issues
• check https://www.python.org/dev/peps/pep-0587/ and how to correct startup/env settings, probably within PythonHandler::initPython()
• samples and tests not changed from python 2.7 -> python 3.8
• exe from python test project doesn't run without manual copy step of python38.dll
• sphinx warnings

C:\projects\pythonscript\docs\source\notepad.rst:77: WARNING: duplicate object description of notepad.clearCallbacks, other instance in notepad, use :noindex: for one of them
C:\projects\pythonscript\docs\source\notepad.rst:85: WARNING: duplicate object description of notepad.clearCallbacks, other instance in notepad, use :noindex: for one of them
C:\projects\pythonscript\docs\source\notepad.rst:93: WARNING: duplicate object description of notepad.clearCallbacks, other instance in notepad, use :noindex: for one of them
C:\projects\pythonscript\docs\source\notepad.rst:515: WARNING: duplicate object description of notepad.setEncoding, other instance in notepad, use :noindex: for one of them
C:\projects\pythonscript\docs\source\scintilla.rst:3483: WARNING: duplicate object description of editor.getCharacterPointer, other instance in scintilla, use :noindex: for one of them
C:\projects\pythonscript\docs\source\scintilla.rst:4580: WARNING: duplicate object description of editor.clearCallbacks, other instance in scintilla, use :noindex: for one of them
C:\projects\pythonscript\docs\source\scintilla.rst:4585: WARNING: duplicate object description of editor.clearCallbacks, other instance in scintilla, use :noindex: for one of them
C:\projects\pythonscript\docs\source\scintilla.rst:4590: WARNING: duplicate object description of editor.clearCallbacks, other instance in scintilla, use :noindex: for one of them
C:\projects\pythonscript\docs\source\scintilla.rst:4779: WARNING: duplicate object description of editor.search, other instance in scintilla, use :noindex: for one of them
C:\projects\pythonscript\docs\source\scintilla.rst:4785: WARNING: duplicate object description of editor.search, other instance in scintilla, use :noindex: for one of them
C:\projects\pythonscript\docs\source\scintilla.rst:4791: WARNING: duplicate object description of editor.search, other instance in scintilla, use :noindex: for one of them
C:\projects\pythonscript\docs\source\scintilla.rst:4797: WARNING: duplicate object description of editor.search, other instance
in scintilla, use :noindex: for one of them
looking for now-outdated files... none found