Corrected default player location 
Added buttons to "add" and "remove" a function in function's lower tab.
Fixed bug that froze function selection by creating a new FunctionCreatedEvent.
Fixed bug in GridManager that changed nodes position when saving project.
SceneMaker now detects changes in Edge positions to decide whether the project has changed.
Hash value is updated after saving project so SceneMaker doesn't ask again if user wants to save changes.