syntax detection based on scope, not grammar

[lucas-clemente]

this allows emmet to work in html/css based languages like hanbdlebars or erb.

[gjtorikian]

Added some tests, but otherwise, thanks! Pushing a new release.

[epogue]

Awesome! Thanks @lucas-clemente!

[davewasmer]

As far as I can tell, this has regressed, but it's pretty confusing. Looking through the Github history, I get two different pictures depending on which commit I use as the starting point (perhaps there was some kind of rebase or other history-rewriting change and this is how Github renders it?):

The history leading up to the change introduced by this PR:
https://github.com/emmetio/emmet-atom/commits/3f206f1313bc166655f7b4acb4934b8cc0c7a0da/lib/editor-proxy.coffee

The history of lib/editor-proxy.coffee (the file modified by this PR), viewed with master as the starting point:
https://github.com/emmetio/emmet-atom/commits/master/lib/editor-proxy.coffee

Not sure what happened, but long story short, this isn't working once again.

[davewasmer]

Happy to try submitting a PR that combines this fix with the current state (which seems to account for JSX), but wanted to be sure first.