Update jade.vim

kill html syntax.

POC:
1.jade
```jade
doctype html
html(lang="en")
  head
    title= pageTitle
    script(type='text/javascript').
      if (foo) bar(1 + 5)
  body
    h1 Jade - node template engine
    #container.col
      if youAreUsingJade < 2
        p You are amazing
      else if youAreUsingJade > 1
        p Get on it!
      p.
        Jade is a terse and simple templating language with a
        strong focus on performance and powerful features.
```


![1](https://cloud.githubusercontent.com/assets/1265888/2693640/bd67b466-c3b7-11e3-9555-1b18352ede5d.png)

![2](https://cloud.githubusercontent.com/assets/1265888/2693641/bd692a4e-c3b7-11e3-8ecd-b6ce849ebce7.png)

![3](https://cloud.githubusercontent.com/assets/1265888/2693642/bd9f252c-c3b7-11e3-9058-6ed6f6d635ef.png)