CLC-4226 - External links in block messages not opening another window or tab

https://jira.ets.berkeley.edu/jira/browse/CLC-4226
More info at
https://github.com/francisbouvier/ng_html_compile/blob/master/src/ngHtmlCompile.js
http://ngmodules.org/modules/ng-html-compile
http://jesusjzp.github.io/blog/2014/07/30/compile-ngbind-angularjs/