Admin UI: compile all Angular views to one file (optimize page load)

All the Angular views are loaded as separated HTML source files.

In order to speed up page transitions, we should aggregate these files to one.

There are three options:

1) inline views to index.html ( grunt-inline-angular-templates )
2) concatenate views to one file e.g. dist.html ( grunt-angular-templates )
3) concatenate views and transform them to JavaScript source ( grunt-angular-templates )

This techniques makes initial page load time little bit slower, but make page transitions faster (and avoid need for "loading spinner" AGPUSH-707).