Half fix for #9855: Don't fuck with margins for open modal dialog on account of Lion non-scrollbars and inconsistencies elsewhere

fixes #10526: Remove custom background on responsive tables and set it in the docs where it should've been originally

fixes #10521: Only remove bottom-border from last row of cells in tbody and tfoot within responsive tables

fixes #10406: Update grid to use width on .container instead of max-width as IE8 improperly computes width

fixes #10115: Default carousel controls and Glyphicon controls should behave the same on small devices and up

Hadn't thought about this until fixes #10137, but it makes sense I
think to have margin on the bottom of thumbnails for spacing when
stacking (or using different grid tiers).

* Update styling of justified nav links to be more mobile friendly
(with all four rounded corners and some margin between items)
* Add note to docs to callout bogus WebKit rendering on component and
example