Creates main overview tab and toolbar. Troy, Jake, Zack
Adds iscancelled, cancel, and isDone implimentations

Manny DeMaio
Louie Mistretta
Merge dev onto dev-sessions
Modifies Method for determining state of activity for session model

Session now checks whether or not it has a start time to determine if it is active.
Setting it to active sets the start time to a non-null date.
Adds end time to cancel functions
Manny DeMaio
Louie Mistretta
Merge branch 'dev-sessions' of github.com:Team-Combat-Wombat/wpi-suite-tcw into dev-sessions
Merges dev-sessions-entity-manager into dev-sessions
Merge branch 'dev-sessions-entity-manager' of github.com:Team-Combat-Wombat/wpi-suite-tcw into dev-sessions-entity-manager