Updated php-markdown - from 1.4.0 to 1.4.1

https://github.com/michelf/php-markdown/tree/1.4.1#version-history

### PHP Markdown Lib 1.4.1 (4 May 2014)

* The HTML block parser will now treat <figure> as a block-level element (as it should) and no longer wrap it in <p> or parse it's content with the as Markdown syntax (although with Extra you can use markdown="1" if you wish to use the Markdown syntax inside it).
* The content of <style> elements will now be left alone, its content won't be interpreted as Markdown.
* Corrected an bug where some inline links with spaces in them would not work even when surounded with angle brackets:

    [link](<s p a c e s>)

* Fixed an issue where email addresses with quotes in them would not always have the quotes escaped in the link attribute, causing broken links (and invalid HTML).
* Fixed the case were a link definition following a footnote definition would be swallowed by the footnote unless it was separated by a blank line.