Added basic sorting functionality: if you click on a header in reqlist, it will sort in ascending order if the elements in the column implement Comparable
Headers titles now change to reflect how it was sorted, and it flip flops between sorting ascending and descending.  -Michael Perrone
added framework for testing, didn't actually test anything. will do that later!  -Michael Perrone
Actually implemented the shell of tests I had previously. -Michael Perrone
Added the same functionality for the iteration list view (and corresponding tests). Also changed '-1' to 'None' for parents in requirement list, and did a little bit of hacking to make the sort still work with that. -Michael Perrone
Merge branch 'team1-sortReqListByColumns' into team1-dev

Conflicts:
	RequirementsManager/src/edu/wpi/cs/wpisuitetng/modules/RequirementsManager/tabs/model/IterationTableModel.java
	RequirementsManager/test_PermissionsLog.txt