* handle js-yaml and underscore libraries with bower (use libraries
downloaded with bower by sym-linking bower_components to libs dir in
static);
* get rid of no longer used angular-filter;
* move libraries without official releases to custom-libs
* simplify file requirements in karma config.
Change-Id: Ie3d1d90c6f2ccc89c7cf91fe0d9dae4b2b88442f