Added Factorial functionality to this project.

This will create a "partial" factorial of a given range of numbers. For a full
factorial, have the start point be "1". Included is a quick unit test in C with
some quick values checked.

I need to switch to SWIG and make it so that I can get everything working and
test using Python. Perhaps tomorrow when my laptop isn't about to die because I
forgot my powercord.
Changed the arguments from "int" to "unsigned short".

No factorial would be able to be generated of a full int, partial or not, and
it cannot be negative. To safegaurd against that I made them unsigned and short
so that it will not be able to run outside of those simple ranges.
Completed the combinations function.

Combinations will attempt to simplify the factorials to be computed as much as
is possible to limit the size of the factorial. I may need to come back in and
change this up some based on the master program.
Updated the README file requirements, change log, and file manifest.

I added the requirement for compilation to be in a C99 compatible environment.
I also listed the new files that have been incorporated into the program in the
file manifest. Finally, I updated the change log to match these new features.

This branch are ready to merge into master and master tagged to v0.0.2.
Merge branch 'mathfunctions'

All changes are being committed and master will now be updated to version 0.0.2
which brings us one step closer to the release.

Conflicts:
	README.md