Replaced tabs in TreeSprite.scala with spaces. Added a getScreenPosition method to NodeSprite.
NodeSprite's getScreenCoordinates was getting the wrong y coordinates. It's fixed now.
the getScreenPosition method was moved from NodeSprite into the Sprite class in the Sage2D library. Now all Sprites can use it.
Made the code for tree visualizations prettier.
TreeSprite, NodeSprite, and TreeVisPanel no longer depend on any Elision/Eva-specific code.
Merge pull request #142 from Cazra/master

Eva cleanup