Hallvord R. M. Steen

@tomasAlabes what do you think of this PR - OK to merge?

(Browsers that do support createSVGMatrix() escape un-harmed thanks to the new try..catch in 2.2 - this wasn't added yet in 2.0 which is the version that still powers the demos...

Seems this is in the add-ons SDK: http://mxr.mozilla.org/mozilla-central/source/addon-sdk/source/lib/sdk/test/httpd.js (but note the "stability": "experimental" status)

Some experiments in feature detection: http://jsbin.com/butaxaziyo/edit?js,output queryCommandEnabled() only returning true inside event handlers is intended to help discover the "works in certain trusted event handlers" support. This may not be...

(It's of course rather easy to detect the false positive feature detection in Fx < 40 - ``` var supported = document.queryCommandSupported('copy'); try{document.execCommand('copy')}catch(e){supported = false} ``` should do the trick....

@JamesMGreene I fixed the merge conflict here. Guess test coverage is still falling slightly, sorry I have not had time to figure out how to fix that.

(It would be nice if this landed before #171)

Probably discussed to death, but if the browser can just keep its UI responsive does it really matter if a script author sometimes makes his/her page freeze by a sync...

Isn't this issue handled by promises and other work on making JS itself more "asyncish"? In other words, I would consider an implementation somewhat obnoxious if it warned me against...

(I admit that I have not tested that code to see if browsers implement sync-xhr-in-promise the way I'd expect them to do it ;). Perhaps we should add a test...