Some formatting in EllipseGeometry.
Add texture rotation to ellipse and circle geometry.
Rotate tangents and binormals of extent when texture is rotated.
Add test.
Add extruded ellipse rendering tests.
Change t texture coordinate of ellipse geometry.
Optimize polyline collection bounding spheres.
Make sensors render in two passes: back face and front face. Also adds ambient light to sensors.
Remove unused variable.
Merge branch 'master' into ellipseTextureRotation
Remove unused variable.
Update based on review.
Give Scene frameState, camera, and screen space camera controller initial state before rendering.
Merge branch 'master' into sensorLighting

Conflicts:
	Source/Scene/CustomSensorVolume.js
Fix after merge.
Merge master into polylineBoundingSphere.
Merge pull request #985 from AnalyticalGraphicsInc/sensorLighting

Sensor Lighting
Consolidate .gitignore files in the root.

This makes it easier to copy various source folders for use in other projects without accidentally ignoring items.
Merge pull request #991 from AnalyticalGraphicsInc/consolidateGitIgnore

Consolidate .gitignore files in the root.
Merge pull request #986 from AnalyticalGraphicsInc/initialSceneState

Initial Scene state.