added bower_components to .gitignore
fixes part of #11117: doc that modal show()/hide() return before animation finishes
Merge pull request #11172 from yokomizor/git_ignore_bower_components

added bower_components to .gitignore
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
Merge pull request #11534 from twbs/doc-async-modals

document that modal show()/hide() return before animation finishes