Switch to CMake and use vcpkg.

[judemille]

Build not tested on platforms other than Linux. Removes dependencies from the build tree, and in general does significant cleanup.

[judemille]

CMake may be painful, but it's definitely less painful than QMake. This whole PR should reduce the codebase's own size, as well as making the build more resilient. This also avoids the library re-exporting all of its dependencies.

[judemille]

Rebased onto current revision.

[judemille]

Now it's actually rebased onto the current revision.