- Implements new format "Copyright 2011-xxxx Twitter, Inc.", which resonates well with our History page and more accurately reflects the copyright status of the repo
- grunt dist to update all the files

Update Gruntfile.js to copy 'dist/' files to 'docs/dist/' with 'grunt dist' task; Fixes #12030: navbar toggle focus state

If the popover's title contains no text, hide it via JS. Previously was
done via CSS's `:empty` property, but that doesn't work in IE8, so JS
it is.

/cc @fat becaue I probably did this wrong <3

* Remove plugin file and put JS inline
* Update grid layout to use tablet columns
* Switch from LESS to CSS for transition
* Pad footer sides for better mobile rendering
* Spacing cleanup

add show/shown hide/hidden events to dropdown + update dropdown links for testing + catch a few missed namespace things