nokogiri-xmlsec

https://github.com/sinisterchipmunk/xmlsec

Adds support to Ruby for encrypting, decrypting, signing and validating the signatures of XML documents, according to the [XML Encryption Syntax and Processing](http://www.w3.org/TR/xmlenc-core/) standard, by wrapping around the [xmlsec](http://www.aleksey.com/xmlsec) C library and adding relevant methods to `Nokogiri::XML::Document`.