Added message div for display error and other messages. Also fixed bug where if frontend validation passed but backend validation failed, class would be unscheduled instead of going back to previous position.
Fixed tests and updated spec for validateAssignments
Added tooltips to rooms
If a teacher is teaching during a block, highlight that block as yellow instead of green.
Added grade range to tooltip
Cells with sections are selectable and when selected, availability is highlighted on grid
Fixed tests and added test for selecting/unselecting cells
Selected section shows up in info panel
Created MessagePanel widget
Add section info panel as separate file