[#39] add two functions to hl JS blocks
[#39] add two functions to hl JS blocks

    - abuse font-lock a little and steal some inspiration and code
      from haml-mode
    - use js-mode's keywords and syntax table to hl specific regions
      of the buffer

mgs/jade-mode,emacsmirror/jade-mode,tjefferson08/jade-mode,brianc/jade-mode