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.
Resolves #10923

Rebased from #10930
Include a note about text-based form control styling

fixes #8824.
Merge pull request #11110 from nikolawannabe/patch-1

Include a note about text-based form control styling
add dots to class name references for consistency
Fixes issue #11122 -- navbar-fixed-bottom border

Enable border-top in .navbar-fixed-bottom
Fixed broken link
Merge pull request #11128 from lipis/patch-3

Fixed broken link in README.md
redo the glyphicons icons list to make icons not blurry on edges /cc @jankovarik
Merge branch 'master' of github.com:twbs/bootstrap
upgrade to html5shiv v 3.7.0
add note about third-party JS, CDNs, and HTTPS
Merge pull request #11137 from twbs/explain-https

add note about third-party JS, CDNs, and HTTPS
Update translation URL
Merge pull request #11141 from vincentchan/master

Update translation sites URL
fix #11144
FIx invalid element selector

`kbd` (keyboard) is right, not `kdb`. :P