Basic keyboard accessibility CSS tweaks

Mostly doubling-up :hover styles to also cover :focus, as a first step
to making the framework more keyboard-friendly.
Additionally, fixed two small markup issues in the docs/examples to
make the "Learn more" large primary button-styled links
keyboard-focusable (as without href they're treated as non-tabable
anchors).
Removed touchstart from bootstrap-dropdown.js.
Cleaned up dirty CSS

Used recess rather than less
Keyboard accessibility in documentation

Removed unnecessary (?) and harmful (from a keyboard access point of
view) tabindex=-1 in the documentation examples.
Revert "Keyboard accessibility in documentation"

This reverts commit a809daf2841f65ffac5030b2c6ce6aea60dd6233.
Leave tabindex=-1 alone

It seems that, as misguided as I personally think it is, ARIA does
indeed want dropdown menus not to behave as regular keyboard users
expect them, killing TAB/SHIFT+TAB in favor of cursor keys. Fair
enough, the issue I have is then with ARIA, not with bootstrap. I would
sugges thought that if you really do want to follow ARIA consistently,
*any* navigation bar should also become an ARIA menu, further making it
impossible for keyboard users to use TAB/SHIFT+TAB to navigate through
it, and that these changes should be reflected in the bootstrap
examples as well...
Revert "Leave tabindex=-1 alone"

This reverts commit 370fa45fbe4ee879a626a67bb4df0ec9495102be.
Tooltip positionning on special cases
Unit test for replacing tooltip inside window
lint + wrong comparison
Test for replacing tooltip when resized
works with fixed test
Arrow replacement
No semicolumns
Fix tooltip positioning for IE8
IE8 defines a placeholder object getBoundingClientRect which breaks the new getPosition() method
Move to new selector interpolation, supported from 1.3.1
reordered access of options in tooltip and popover to allow overriding data attrs from js
fix typo
Fixes #6794: incorrect docs mention of th element
Merge branch '2.3.0-wip' of github.com:twitter/bootstrap into 2.3.0-wip