chore(build): switch build to grunt 0.4

This is first-shot attempt at switching our build to Grunt 0.4.x. It doesn't attempt to refactor / simplify the build (which we probably could do with using grunt plugins for testacular, html2js etc. instead of providing our own implementation). 

The immediate goal for me was to have a working build on the Jenkins-CI server which is broken atm, see: See https://github.com/angular-ui/bootstrap/issues/207