Fix #1605, Sandcastle drop-downs don't work in Firefox
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.
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
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
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
Merge remote-tracking branch 'origin/master' into dataSourceBrowser

Conflicts:
	Apps/CesiumViewer/CesiumViewer.js
	Source/DynamicScene/CzmlDataSource.js
	Source/DynamicScene/DataSource.js
	Source/DynamicScene/DataSourceDisplay.js
	Source/DynamicScene/GeoJsonDataSource.js
	Source/DynamicScene/StaticGeometryPerMaterialBatch.js
	Source/Widgets/widgets.css
	Specs/DynamicScene/GeoJsonDataSourceSpec.js
	Specs/MockDataSource.js