Dropdown in panel header does not inherit its colors

Fix for issue #10627
Removed the unnecessary override and the !important from .wrap

In the sticky footer example there were some weird stuff..
Same fix for the navbar example of sticky footer
remove comma separating the color and the color-stop in -webkit-linear-gradient in the #gradient .vertical mixin.
Fixes #10620: remove gradient on buttons for IE9 in theme.less due to bleed through with rounded corners
Merge branch 'master' of github.com:twbs/bootstrap
spacing
Merge branch 'master' into pr/10656

Conflicts:
	dist/css/bootstrap.min.css
more spacing
Merge pull request #10729 from lipis/patch-2

Removed the unnecessary override and the !important from .wrap
Merge pull request #10893 from Shaun-Dychko/patch--webkit-linear-gradient

remove comma separating the color and the color-stop in -webkit-linear-gradient in the #gradient .vertical mixin.
run grunt on last commit for gradient syntax change
Fixes #10601: Use overflow-y: auto; for navbar collapse instead of visible to better enable scrolling on Android 4.x
Change upper case to lower case
Merge pull request #11192 from ZDroid/typo

Change upper case to lower case
Merge branch 'master' of https://github.com/twbs/bootstrap into develop