chore(docs): ensure the "Improve this doc" button is clickable

Closes #6631
docs(ngRepeat): Separate animation class in new lines

Moving to new lines & making it bold to avoid confusion
when they r all in same line without any separation

Closes #6633
docs(route.js): changed html entities lt gt to < and >
docs(versions): rework the version info extraction

The docs were relying on the grunt/util module for getting version info
but this was unreliable and full of custom regexes.  This is moved into
a new version-info module that makes much better use of the semver library.
chore(build): refactor build version information
docs(tutorial): display button icons (Previous, Live Demo, ...)

In relation to https://github.com/angular/dgeni-packages/pull/8

Closes #6641