Fix SceneTransforms.wgs84ToWindowCoordinates for SCENE2D.
Add unit tests, fix scene.morphTo* to work with unit tests.
Use PolylineCollection for time-dynamic polylines

In order to keep feature parity between static and time-dynamic polylines,
PolylineGeometryUpdater was using PolylineGeometry to render lines that
were changing every frame.  Obviously this generated a lot of garbage and
would kill performance when using a lot of time-dynamic lines (like the d3
demo does).  In order to improve performance, I've updated the dynamic
lines to use PolylineCollection instead; which greatly improves performance.

The only feature PolylineGeometry has that PolylineCollection lacks is
per-vertex colors; but since the DataSource layer doesn't expose that feature
yet; this is okay for now.  Of course when we have dynamic buffers,
this problem should just go away.
Update README.md
Changes after review

1. Add `Scene.id` property to uniquely identify a scene.
2. Use `Scene.id` to create one PolylineCollection per scene in `PolygonGeometryUpdater`.
3. Improve tests for dynamic polylines created by `PolygonGeometryUpdater`.
Fix misspelling.
Fix Matrix2 doc example.
Remove ancient remnant of the JSLint eclipse plugin.
Fix crash when material source uses Windows line endings.

* Also would crash if uniform in source used extra spaces or tabs.
Fixes to sample code for Matrix2 and Matrix3 classes.
Async picking of rasterized features in imagery layers.

For example, by using the WMS GetFeatureInfo service.
Fix a couple bugs in SceneTransforms.wgs84To*Coordinates that didn't properly check for undefined. Updated tests to use better positions in Columbus view.
Show position of selected feature.
Update CHANGES.md
If feature position is not known, use pick location.
Pick the front of the ellipsoid even below its max radius.
Use > instead of >=.
Add support for MapInfo GetFeatureInfo.
Add support for Esri WMS servers.
Add support for unknown GetFeatureInfo responses.