Webapp scaffold

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Had to fix a few things though:

-  hotfix the inclusion of Glyphicons by copying the images in
src/app/images. See src/app/styles/main.scss. Also see
https://github.com/yeoman/generator-angular/issues/196
- tweak the tasks order in Grunt's build process. See
https://github.com/yeoman/generator-angular/issues/193#issuecomment-1729
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