Added framework for defining test metrics, which will allow us to report
statistics about the classifiers under test.

Modified XORTestNoBackprop to use this new framework
Removed dead code
epsilon for correctness now has a default, but allows user to specify their own if needed
Merge branch 'master' of github.com:theJenix/ABAGAIL into tester

Conflicts:
	src/opt/test/XORTestNoBackprop.java
Merge branch 'tester' of github.com:theJenix/ABAGAIL into tester
Merge pull request #5 from theJenix/tester

Testing framework