[Feature Request/Idea] For certain bindings and references such as foo-bar the compiler uses bracket notation.

[GarrettGeorge]

Inspired by issue #1613 I think instead of simply throwing an error we could use bracket notation when bind:, ref:, etc. are binding or referencing, respectively, a value like ref:foo-bar.

Example Output:

this.refs['foo-bar']

Alternatively we can throw an error that's more specific than the one that Acorn throws, but since bracket notation is syntactically correct I figure it makes sense to support it.

I'm interesting in something of this nature as being my first contribution towards Svelte (the JSConf EU talk got me inspired).