Fixed essay answers so answers can have newlines
Merge pull request #44 from goehle/devupdates

Newlines in Essay Answers
Create MatrixCheckers.pl

Custom answer checkers for a basis, etc.
Create MatrixReduce.pl

Macros for rref, elementary matrices, etc.
Create MatrixUnits.pl

Macros for generating n x n (n=2,3,4) matrices with integer entries that have inverses with integer entries
Merge pull request #48 from paultpearson/patch-3

Create MatrixUnits.pl
Merge pull request #47 from paultpearson/patch-2

Create MatrixReduce.pl
Merge pull request #46 from paultpearson/patch-1

Create MatrixCheckers.pl
Merge pull request #4 from openwebwork/develop

Develop