MapGate implemented -- read desc

MapGate fully implemented — issue: Path is not relative, only works on
creator’s computer.
MapGate implementation — Added button to find MapGate path in
CustomOptionsPanel, LevelEditorDisplay, and EditingPanel classes.
EnhancedButton Class added — used for cardinal direction button
controls: you can now press and hold to move.
Fixed LevelEditor bugs — syntax error for Externalizable in Potion Class
Fixed DialogBox issue — When too many lines were being appended it
would result in DialogBox lagging behind. Fixed by initially allocating
memory to DialogBox’s textArea.
Added AnalysisPanel class — not fully implemented: use SplitPane and
TreeComponents to view statistics of current Entities created in
LevelEditor.