The BOND_GBC_PATH environment variable is no longer consulted, and the
Haskell toolchain will _not_ be used even if it exists.
At the moment, the downloaded gbc is amd64 only.
* Make Bond always build as a static lib.
* Bond's CMake currently isn't written to be able to produce DLLs.
There's a special dllimport/dllexport dance that would need to be
done.
* Apply patch so that Bond doesn't force Boost static libs.
* Apply patch to omit installing Bond's copy of rapidjson.
* Clean up empty bin/ directories, now that vcpkg is more strict.
