Added Region class
Added MigLayout to build
Gfx: Added drawGrid()
Added EditorColours
Region: Added methods to retrieve L/R/T/B edges
EditorFrame: Now uses MigLayout
EditorPanel: Added scalable grid background
Vec2: Added toString()
EditorPanel: Zooming and panning implemented
Class comments
Region: Added getNormalisedCoord()
Vec2: Removed class name from toString()
EditorPanel: Zoom toward centre.  Stopgap until focusing is done.
EditorPanel: Zoom wasn't taking zoomRate into account
EditorPanel: Panning now interacts correctly with zooming.
EditorPanel: Added functions to map mouse pos into world-space
Line2: Now serialisable
Vec2: Now extends from Point2D for graphics interop.
Vec2: Added scalar arithmetic methods
Region: Added toString()