Adds syntax for Identifiers in labeled statements

    { $: 'now this label has syntax highlighting' }

Using this RegExp `[a-zA-Z_$][0-9a-zA-Z_$\-]` 
instead of just checking for `\w`.

Although it doesn't cover the full range of characters an Identifier
can be it does work for the 98%.
Merge pull request #64 from goatslacker/patch-1

Adds syntax for Identifiers in labeled statements