Add support for Windows

[andrie]

@jeroen, as discussed at eRum 2018, I would appreciate your help to create the Windows DLLs so we can build this package for Windows.

[andrie]

Hi, @jeroen, I'm getting ready to push an update of the package to CRAN. If you can help with getting the Windows DLLs prepared, I would appreciate it.

[jeroen]

Thanks, I'll try to have a look soon. I tried before but got stuck on all the dependencies.

If you want to help, try creating a mingw-w64 package to upstream msys2 . From there it will be easier for me to adapt it for rtools.

[andrie]

Aha, that's helpful, thank you. The two main dependencies are pango and ttf-dejavu and I found build packages for both of these in upstream. Most of the other dependencies we don't need, since you need Lua, Python, Ruby, etc. only for integration with those languages.