use showdown.js to format textchat messages in markdown
auto translate urls to links and set target='_blank' to all links
Merge pull request #44 from Paulloz/textchatformatting

Format text chat messages with Markdown.
Auto-translate urls to Markdown link.
Set all link's target attribute to _blank.
Fixes #9

Conflicts:
	src/frontend/modules/textChat.coffee