Swapping REXML SAX with Nokogiri SAX
Finish converting over to a nokogiri streamer.
We need to use ruby's non-blocking I/O to listen to the TCP stream and push the data to the Nokogiri SAX "PushParser" instead of a normal Parser, because otherwise we block inside of the Nokogiri C code while the GIL is locked.
Unescaped XML barfs REXML text nodes!
Adding nokogiri gem dependency
Merge 'b54f4801ec8bc03bf4eadf5fae7a117fc2ba4266' on master from hoxworth/xmpp4r

Conflicts:
	lib/xmpp4r/streamparser.rb