Use @HtmlSafe annotation for Jira 6.1 escaping problem solve, update jgit version

Hello.

According to https://developer.atlassian.com/display/CONFDEV/Enabling+XSS+Protection+in+Plugins Html method suffix should solve problem HTML escaping in velocity templates, but it does not work for v6.1 for some reasons. Fix it by add dependency to velocity-htmlsafe and use @HtmlSafe annotation.

Also refresh jgit version and minor changes for compatibility.