Fix #1605, Sandcastle drop-downs don't work in Firefox
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
Fix #1603

#1603 only affected non-time-varying data sources.  After the last revamp of the Property system,  `DataSource.getIsTimeVarying` is actually no longer needed and removing it fixes a whole host of issues similar to #1603.
Add missing documentation.
Add specs and fix problem uncovered by them.
Remove comments about IE8-style button mapping.
Merge pull request #1615 from AnalyticalGraphicsInc/sandcastle-select

Fix #1605, Sandcastle drop-downs don't work in Firefox
Merge pull request #1619 from AnalyticalGraphicsInc/issue1603

Fix #1603
Merge branch 'master' into dynamicScene-buffering

Conflicts:
	Source/DynamicScene/DataSourceDisplay.js
Tweak CHANGES.md
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