Add Inline Tag support.

As discussed at visionmedia/jade/pull/1323, [Jade](visionmedia/jade) now can embed tags "inline" in plain text, using the delimiters `#[` and `]`. For example:

```jade
  a(href='/') #[i Emphasized] Home Page
```

[haha it looks like github syntax coloring needs an update for this too] becomes:

```html
  <a href="/"><i>Emphasized</i> Home Page</a>
```

This is quite useful!

I made two new syntax matches, `jadeTagInlineText` and `jadeTagBlockChar`, and three new syntax regions: `jadePipedText`, `jadeTagBlockText`, and `jadeTextInlineJade`. Each of the three "Text" items `contains` the new `jadeTextInlineJade` region as well as the pre-existing `jadeInterpolation` region.

I also added a `\+` to the regex for `jadeBlockExpansionChar`, so that it can handle more than one space between the colon and the next tag. This is consistent with Jade's behavior.