Merge pull request #11521 from valera-rozuvan/patch-1

Update dropdown.js
- Firefox placeholder text is faded out and not the full color. Adding opacity:1 to it returns it to the proper color
- (this is a re-commit since I messed up my branch last time and failed the travis build)
Merge pull request #11526 from erikflowers/firefox-placeholder-fix

Firefox placeholder text is faded out and not the full color.
Merge pull request #11514 from twbs/navbar-text-float-breakpoint

Fix #11513: Don't always float navbar-text
add explanatory comment Re: #11526
fix #11089: document modal show+shown events' relatedTarget property
fixes part of #11117: doc that modal show()/hide() return before animation finishes
add support for button dropdowns in justified button groups
Add 'in' to complete thought

Simple grammar fix.
Merge pull request #11172 from yokomizor/git_ignore_bower_components

added bower_components to .gitignore
removed color treatment of outline
add role form for horizontal form example
Make it clear there's a nested media element in the first example
Merge pull request #11578 from barraponto/patch-1

Make it clear there's a nested media element in the first example
Merge pull request #11567 from neilhem/master

add role form for horizontal form example
add more missing role="form"-s
Issue #11550 : Easily copyable classes

Removed all the periods. Tested in Chrome and Firefox
(current versions). In Chrome you get a stray newline when
triple-clicking, in Firefox it is clean.

fixes #11550
Merge pull request #11534 from twbs/doc-async-modals

document that modal show()/hide() return before animation finishes
finish up moving content, tweaking styles
Merge branch 'master' into docs_derp