build: windows: add pywinmake and simplify winmake script

Building libjami should now be doable using:
- init   : git submodule update --init
- install: pip install extras/scripts/pywinmake
- contrib: python extras/scripts/winmake.py
- libjami: python extras/scripts/winmake.py --base-dir compat/msvc

NOTE: breaks libjami output location

TODO: fix plugin build

Change-Id: Ic6b25d00103f0ea68d8ab7954f8345f1648e0381

.gitignore

@@ -99,9 +99,6 @@ tools/.vscode/
 *_wrap.h
 *_loader.c
 
-# Windows
-*.exe
-
 # Mac
 .DS_Store
 build-macos*
@@ -112,8 +109,9 @@ build-macos*
 /extras/tools/libtool-*.tar.xz
 
 # Windows native build
-/contrib/build/
-/contrib/msvc/
+x64/
+Release/
+Debug/
 
 # iOS
 /build-ios*
@@ -144,4 +142,4 @@ compile_commands.json
 *.cmake
 CMakeCache.txt
 Testing
-CMakeFiles
+CMakeFiles