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 issue #11122 -- navbar-fixed-bottom border

Enable border-top in .navbar-fixed-bottom
Fixes #10522: Enable use of form validation class on .radio, .checkbox, .radio-inline, and .checkbox-inline
Merge branch 'master' of https://github.com/jeonghwan-kim/bootstrap into jeonghwan-kim-master

Conflicts:
	dist/css/bootstrap.min.css
fixes #11139: add position: relative; to .modal-dialog so that z-index takes effect
Fixes #10433: Navbar z-index refactor

* Resets the default navbar z-index to auto at a certain breakpoint
* Adds fixed navbar z-index var to fixed bottom navbar (previously only on fixed top navbar)
Fix up padding on default navbar example
Remove default z-index on navbar and only set on static and fixed variants
Merge pull request #11188 from twbs/navbar_zindex_auto

Fixes #10433: Navbar z-index refactor
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