Update: Implement f_capability unit tests and improve existing unit tests.

Update: Implement f_capability unit tests and improve existing unit tests.

Add tests for f_capability functions.
This includes my first go at mocking functions using function wrapping.
It seems that the linker is limited on how it handles function wrapping.
I cannot simply wrap functions pulled in via a library.
To work around this I implemented another Fake build settings file for handling this.
This is not an ideal situation and adds a bit of extra work.

The environment variable settings for LD_LIBRARY_PATH needs to also support the work parameter.

These changes expose a logic flaw in the if/else logic of the Fake program.
That bug is not fixed in this commit, it is simply noted in this commit log.