Ruby fixes and features

* fixed greedy strings
* added support for syntax highlighting within string interpolation
* added support for `__END__` keyword

#### OLD

![screen shot 2013-08-24 at 12 46 25 pm](https://f.cloud.github.com/assets/58729/1021077/a8b5f370-0cdd-11e3-8983-cddf82a38b88.png)

#### NEW

![screen shot 2013-08-24 at 12 47 38 pm](https://f.cloud.github.com/assets/58729/1021083/048abdfc-0cde-11e3-994b-ab99c8072fcf.png)

here is the same text highlighted by github
```ruby
"me" && "you"

#string interpolation
12.times do |x|
  "Chapter #{x+1}:"
end

__END__
if (parsed)
  "this should not be classified as a string"
else
  raise "Epic Fail"
end
```