Change implicit textOnly fixes to only apply to indented block content

Fix for some of the spurious fixes mentioned in https://github.com/visionmedia/jade/pull/1036

I removed the initial test that ran before the replace operation, not sure if that did anything.

This is untested and I'm not *positive* it works (I'm a little fuzzy on how ^ and newlines interact in multiline mode, if regexes can still span multiple lines).
Fix character class for end-of-line attributes

This test will be fooled by a block like this:

```jade
script weirdness.
  var example = "this is broken"
```

But that's an already-broken edge case, while this is common:

```jade
style(type='text/css', data-example="There's space in here!")
  /* this block would get passed over because the tag had white space before the newline */
```

In lieu of a more robust rule, we'll just let the edge case fall beneath the cracks.
Fix regex backreference

Every time I use backreferences I think it's $1 instead of \1.
Correct script type test
Merge pull request #3 from stuartpb/patch-1

Change implicit textOnly fixes to only apply to indented block content