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
Remove comments about IE8-style button mapping.
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
Merge remote-tracking branch 'origin/master' into dynamicScene-buffering
Changes after review.