under `tools/` add some scripts to invoke the build system to build all
deps for vbam and vbam itself:
- `tools/linux/builder`
This builds a mostly static linux binary with a few dynamic deps for
xorg and wayland. Using gtk3. This will run on just about any dist.
- `tools/osx/builder`
Builds a static mac app targetting 10.7.
- `tools/win/linux-cross-builder`
Builds a static windows binary using the mingw-w64 toolchain.
- `tools/win/msys2-builder`
Builds a static windows binary in the MSYS2 environment, this may be
suffering from a few regressions.
Change some cmake code to support the build system, refactor a few
things in it.