Tweaked schedule view scheduling a bit.
Adjusted schedule view scheduling algorithm to take currently ongoing period into account.
Fixed ghost prerequirement graph edges being drawn in schedule view.
Fixed courses in schedule view not being properly selected if dragged before being clicked.
Disabled text selection of course divs in schedule view.
Schedule view: Changed course cursor type to 'not allowed' when course is locked.
Schedule view: fixed 'course locked' checkbox not being disabled on all browsers.
Schedule view: Fixed prerequirement graphs not being drawn properly on Opera.
Schedule: Disabled text selection on the whole #plan div.
Schedule: Fixed one z-index issue.
Schedule: Fixed two scheduling bugs.
Schedule: Fixed courses being scheduled on to ongoing period.
Schedule: Initial css for period warning backgrounds.
Schedule: Course divs now display lock icon when course is locked.
Schedule: Added linear gradient css rules for other browsers too.
Merge: Merged period warning background from a topic branch.
Schedule: Added prerequirements list for selected course.
Initial implementation of prereq satisfiability checking.
Some improvement attemps.
Schedule: Added red background class for periods that have already passed, but had course instance for the selected course.