Added constraint for courses being overlapped
Add needs_computers attribute to course object and input xml
Merge branch 'tr' of https://github.com/donnell74/CSC-450-Scheduler into computers

# By Gregory Donnell
# Via Gregory Donnell
* 'tr' of https://github.com/donnell74/CSC-450-Scheduler:
  Added constraint for courses being overlapped

Conflicts:
	genetic/constraint.py
	genetic/scheduler.py
	gui/guiClasses.py