Reduce specifity and cleanup CSS
First pass as stripping out unnecessary decendant selectors, removing excessive clear-fixing and other minor changes. Slight change to how list-horizontal mixin works - you can now pass in a list item selector - this helps reduce specificty by not relying on the UL root selector. Start general shift to removing as many element selectors as possible and ony using classes.
Review and clean up font icon variables, make sure every icon has a unique variable in _varaibles and is used in the relevant partial, make the actual icon font a variable also to make it easiser to globally change the icon font.
Change Flipslide, style nodes and comments, search block
Change FlipSlide to Mega Nav, make comment and node submitted and meta markup consistant, add card styles and start refining how Responsive menus will work in the header and leaderboard regions, also how the search will work in those regions. Restyle search to use a button by default. In short this is the first commit that starts pushing the Standard theme towards being a real usable theme, and opening the door for the AT Minimal theme to come back as a minimalist alternative.
Remove at-root, add border to list style seven tabs
Previously AT used @at-root as a way of making RTL extremely obvious in the code, however this is really an abuse of at-root and we should use ampersand pre-pend.
Add group for the vertical tabs, no idea how this was working before and i totally forgot you have to do this, also fix double escaping in confirmation message by using the @method rather than !method in drupal_set_message() since we use other markup as well.