Enable asynchronous geometry processing in DynamicScene.

1. GeometryVisualizer now creates static geometry asynchronously.
2. `Clock.canAnimate` was added to prevent the clock from advancing time even when `shouldAnimate` is true
3. Visualizers' update functions now return a boolean value indicating if it is okay to advance time.
4. `DataSourceDisplay.update` now returns false if any of the visualizer update calls return false.
5. The `Viewer` assigns `Clock.canAnimate` the result of `DataSourceDisplay.update`, which prevents time from animated if asynchronous geoemtry is processing.
6. `Viewer.allowDataSourcesToSuspendAnimation` was added to control this behavior in client apps.
Default allowDataSourcesToSuspendAnimation to true.
Update CHANGES.
Remove Google Chrome Frame

Google has discontinued Chrome Frame and prints a console message indicating it no longer prompts.

`Google Chrome Frame is being retired, so the CFInstall.check method no longer notifies the user; see http://blog.chromium.org/2013/06/retiring-chrome-frame.html for more information.`

Fix #1376
Add missing documentation.
Add specs and fix problem uncovered by them.
Remove comments about IE8-style button mapping.
Merge branch 'master' into dynamicScene-buffering

Conflicts:
	Source/DynamicScene/DataSourceDisplay.js
Merge remote-tracking branch 'origin/master' into remove-chromeframe

Conflicts:
	CHANGES.md
Matrix3.inverse memory pressure

`Matrix3.inverse` was creating a new temporary `Matrix3` instance every call; I've updated the code to just use the result parameter when provided.
Merge pull request #1620 from AnalyticalGraphicsInc/matrix3-inverse

Matrix3.inverse memory pressure
Try harder to get error messages through to old browsers.
Further refinement of WebGL error on old browsers.
Remove most old browser detection by using more compatible code.

* createTextNode instead of textContent
* setAttribute for button type
* querySelector instead of getElementsByClassName
Merge pull request #1618 from AnalyticalGraphicsInc/remove-chromeframe

Remove Google Chrome Frame
Merge remote-tracking branch 'origin/master' into dynamicScene-buffering
Changes after review.
Fix memory pressure issue with StaticGeometryPerMaterialBatch

We were never assigning the scratch variable we use to store the material in `StaticGeometryPerMaterialBatch`, which caused us to create a new material every frame.
Default StaticGeoemtryPerMaterialBatch material to undefined.
Merge pull request #1622 from AnalyticalGraphicsInc/material-bach-memory

Fix memory pressure issue with StaticGeometryPerMaterialBatch