Whitespace fixes and tweaks.

* Tabs were used to layout the hilink stuff, now it's just spaces
* A bit of trailing whitespace was removed in various areas
Renamed Quote to jsonQuote

* I also HiLink'd jsonQuote back to Quote for backwards compatibility.

I think it's better practice to match to a language specific highlight
group, then link that back to a major group as it affords colorscheme
designers more control.
Adding jsonNoise group

This gives a specific highlight group to `:` and `,` characters.
Merge pull request #14 from amadeus/tweaks

Fixed whitespace incosistencies, jsonQuote matchgroup renaming, and new jsonNoise grouping