filter_styles not working

[veesahni]

Looks like issue #38 is back.

Given the following:

content = "Hello *github*
<style type='text/css' media='screen'>
p{margin:5px}
</style>
"
puts RDiscount.new(content).to_html

Expected output (since filter_styles was not enabled):

<p>Hello <em>github</em></p>
<style type='text/css' media='screen'>
p{margin:5px}
</style>

Actual output (with RDiscount 2.2.0.2):

<p>Hello <em>github</em></p>