add new vars for common border-radius, upping border-radius of inputs to 4px; add border-radius changes to -large, -small, -mini for buttons and paginations

add new vars for common font-sizes and paddings with large, small, and mini components; resize pagination and buttons to better match each other

https://github.com/twitter/bootstrap/issues/4508

should fix this issue

fixes #4044: make z-index of tooltips same as fixed navbar so they overlay it if generated from within

update button styles to use updated 14px base font size, align carets to others with no opacity changes

fix dropdown vars and make hover state be link color again, add gradient to dropdown link hovers, fix caret positions and active states on nav tabs, tweak nav link padding

remove popoverarrows mixin, relegate code to tooltips and popvers since we only used them once each; this fixes the problem of broken tooltips in 2.1

use variablef or wells background-color, update docs for glyphicons license mention, update popovers to remove that thick border and make them look mo betta

implement ie7 fluid tests and semantic.gs IE7 hack for rounding in ie7; not perfect, but mostly solid