Gauss Jordan

Mostly working!
Gauss-Jordan and RREF

Most of the problems have been ironed out now. Most importantly,
functioning error checks so the program doesn't come unglued by
dividing by zero.
Minor Changes
NC
Almost Final Code
A few earlier changes
Won't sync till these go
Merge branch 'contribution' of github.com:jancojt/linear-algebra-summer-2013 into contribution