added uptri flag and diagonal zero-ing, note: breaks tests
updated tests to threshold adjacency matrix to pass with new uptri and diag zero-ing
Merge pull request #16 from cgallen/fix_diag

added uptri flag and diagonal zero-ing, updated tests
Merge branch 'master' of https://github.com/fperez/brainx
Merge branch 'master' into edits--needed to fix conflicts with util.py because I added some of my own functions I'm not pushing

Conflicts:
	brainx/util.py