queryCommandEnabled/Indeterm() for an unsupported command should throw

[GoogleCodeExporter]

Some richtext2 tests fail browsers that throw an exception for 
queryCommandEnabled("unsupportedCommand") or 
queryCommandIndeterm("unsupportedCommand"), namely RTE2-QE_garbage-1_TEXT-1 and 
RTE2-QI_garbage-1_TEXT-1.  The spec requires throwing:

http://dvcs.w3.org/hg/editing/raw-file/tip/editing.html#querycommandenabled()

This has always been IE's behavior, and Gecko and WebKit are being updated to 
match it:

https://bugzilla.mozilla.org/show_bug.cgi?id=742240
https://bugs.webkit.org/show_bug.cgi?id=83993

Please change RTE2-QE_garbage-1_TEXT-1 and RTE2-QI_garbage-1_TEXT-1 to expect 
exceptions instead of returning false, to match the spec and browsers.

Original issue reported on code.google.com by Simetrical on 15 Apr 2012 at 9:53

[GoogleCodeExporter]

Actually, after discussion on the WebKit bug, it's not clear what we want.  It 
might be best not to test this at all until we reach a conclusion.  Either 
that, or accept both throwing and returning false/empty string, and only fail 
browsers that return true (which I don't think any do).

Original comment by a...@aryeh.name on 24 Apr 2012 at 11:42