As it turns out, you have to declare your link directories before you
use them in cmake, otherwise your executables/binaries will have no
knowledge of them.
This should fix travis builds for mingw.
Add bulk of the platform file for linux, change the compilation target
from shared library to executable for linux, provide necessary changes
to make it compile & load the stub of a process.
Make sure functions are marked as stubs where needed, and implementation
is expected.
Step 1 on road towards Linux.
Remove windows-specific code, stub it out where needed and make sure we
can still compile it the way it is.
Take care of Travis' build matrix to include new build configuration.
Install new packages.