jsComment updates

[amadeus]

Removed some seemingly needless regexes, updated to match consistency.

@bounceme Can you see if this branch fixes anything with the comment stuff you mentioned?

[bounceme]

i think this fixes those issues

[amadeus]

Oh interesting, I wonder if it was due to this weird regex:

syntax region  jsComment        start=+^\s*\/\/+ skip=+\n\s*\/\/+ end=+$+ contains=jsCommentTodo,@Spell fold extend keepend

I wasn't sure what in the hell it was supposed to do... Oddly specific with a strange skip mechanism. Seemed like a recipe for bugs.