Fix margin-bottom on dropdown (navbar-fixed-bottom).
Fixes #14990: Media bodies take up full width

Signed-off-by: Beatrice Peng <bpeng@pivotal.io>
Add Wall of Browser Bugs entry for #11266, #13098

[skip sauce]
Merge pull request #15415 from twbs/webkit-bug-139848

Add Wall of Browser Bugs entry for #11266, #13098
fix "propertes" typos in comments
automatic grunt dist
Merge pull request #15307 from vsn4ik/part_of_15148

Fix part of #15148.
Merge pull request #15391 from stubbornella/master

Fixes #14990: Media bodies take up full width
automatic grunt dist
grunt