Implemented Infinite Canvas
+ Modified DragCanvas to enable dragging node outside canvas for infinite canvas
+ Modified ZoomBorder to work with current canvas structure
+ Added New Grid Line (EndlessGrid)
  - New grid line design by EB
  - Redraw Grid Line if window resize (to support any resolution)
  - Grid Line follows viewport in a seamless manner (simulating infinite grid line)
Moving constant variables from Endless Grid over to new Configurations class.
- Added Unit Tests for pan action in canvas
- Added Unit Test for fast zooming in and out of canvas.
Merge pull request #517 from l2obin/InfiniteChocoBits

Implemented Infinite Canvas with Endless Grid