feat(Grunt): add source maps to all min files

Generate source map files when build step is ran and adds source map
headers to all min files.

Source map url must be appended to the min file otherwise the line
offsets will be off.

Inspired by Ryan Seddon (PR #2858)

Closes #1714
chore(minErr): replace ngError with minErr
chore(ngdocs): update lunr to 0.4.0
fix(jqLite): allow override of jqLite.triggerHandler event object
chore(ngdocs): allow user to press escape key to close docs search
fix(ngMock): ensure mocked window still provides window.location functionality
feat(ngdocs): support popover, foldouts and foldover annotations
feat(ngdocs): provide support for user to jump between different versions of the angularjs documentation
chore(ngdocs): provide test code for lunr search in docs
chore(ngdocs): change minimum search length requirement