Well. Seems like I did it.
Thanks you for agreeing to help me from the beginning. Also thanks for this project and its heading.
I will leave instruction on how I did it:
Required knowledge: windows command line commands (simple) and PATH variable editing
Install GitHub Desktop
Add C:\Users\*Your UserName*\AppData\Local\GitHubDesktop\app-1.5.1\resources\app\git\cmd to PATH
Copy files from msys/bin (bash.exe is in it) and move them to C:\Users\Spar\AppData\Local\GitHubDesktop\app-1.5.1\resources\app\git\usr\bin
Install MINGW 32-bit or MINGW 64-bit respectively.
Add *path to mingw*/bin to PATH
Win + R. Type cmd to open console
Type cd /
Type git clone https://github.com/capr/multigit luapower
Type cd luapower and mgit clone https://github.com/luapower/luapower-repos
Type mgit clone-all and wait
See bundle commands list. Test that everything is working: mgit bundle -o fat.exe
The window's WNDPROC is bound to MessageRouter.proc which calls the window's __handle_message() method which calls the WM_PAINT() method or the on_paint() method. If you're using CairoPanel, that descends from BitmapPanel which defines the on_paint() method. Hope this helps.
Although you already declined, I must bring back wxlua.
There is a fine and well maintained github repo at https://github.com/pkulchenko/wxlua (for Win/Linux/OS-X).
I'm using it as it is bundled with ZeroBrane Studio. The wx binding from ZBS plays well together with bin/mingw32/luajit.exe, but with bin/mingw64/luajit.exe I get errors (wx.dll is no valid win32 application). So I'd need a 64bit dll.