+ Class EditorCanvas
~ Code adjustment in EditorGUI to use the new class

Added a new Class ( EditorCanvas ) similar to Draw Component which
represents the canvas my editor is using. In this class i implement your
method drawGrid(Graphics g) and the setter for Color and GridInterval.
With this customized JSVGCanvas i can call the drawGrid Method out of
EditorGUI.

Signed-off-by: Imkerix <Imkerixus@gmail.com>