refactor ellipse computation into functions
finished extrusion
tests
circle geometry extrudes correctly
Merge branch 'batching' into extrudeEllipse

Conflicts:
	Source/Core/EllipseGeometry.js
Merge branch 'master' into extrudeEllipse

Conflicts:
	Source/Core/EllipseGeometry.js
use GeometryAttributes object
Merge remote-tracking branch 'agi/master' into extrudeEllipse
minor cleanup
Merge branch 'master' into extrudeEllipse
sandcastle example
Merge pull request #942 from hpinkos/extrudeEllipse

Extrude ellipse