tests/fixes: Fixed up several bugs by writing unit tests

There is now a good barage of unit tests that the queue goes through,
some of them have actually found bugs that I have fixed and included
with this commit.

The tests now include several new size, push, and pop tests, with the
inclusion of circular buffer checks. No new features have been added,
just some condensing of the tests for the queue (unecessary right now),
and bug fixes.