Expose WebGL context options via CesiumWidget and Viewer

Also cleaned up some Specs, particularly for Scene and added specs for context options to all three classes.
Tweak tests to pass on Firefox.
Merge pull request #866 from AnalyticalGraphicsInc/issue841

Expose WebGL context options via CesiumWidget and Viewer
Switch to minified version of dojo 1.9.

Delete uncompressed and dojox files.
Remove references to dojox
Merge pull request #865 from AnalyticalGraphicsInc/upgrade-to-minified-dojo

Switch to minified version of dojo 1.9.
Remove scratch bounding sphere for 2D that made the last computed bounding sphere the same for all polylines.
Use a scratch bounding sphere per polyline.
Merge pull request #868 from AnalyticalGraphicsInc/disappearing2DPolylines

Fix polylines disapperaing in 2D.
Merge branch 'master' into batching
Merge branch 'batching' into extrudePolygon