Fixes #14348: Add visibility styles to collapse and tab content to match .hidden
Update print.less from source (html5-boilerplate). Simplyfy table style.
Less: Remove empty lines and blanks.
Update dev dependencies.
Update Ruby dependencies.
Merge pull request #14458 from twbs/npm-deps

Update dev dependencies.
Merge pull request #14453 from vsn4ik/less_empty_lines

Less: Remove empty lines and blanks.
Make `popover-arrow-color` default to `popover-bg`
fix nav links to end with / to avoid 301 redirect
grunt
Merge pull request #14465 from kaime/master

Make `popover-arrow-color` default to `popover-bg`
Merge pull request #14452 from vsn4ik/update_print_less

Update print.less from source (html5-boilerplate).
grunt
Merge branch 'master' into sr_friendly_hidden_content

Conflicts:
	dist/css/bootstrap.css.map
	dist/css/bootstrap.min.css
typo
Merge pull request #14444 from twbs/sr_friendly_hidden_content

More screenreader friendly hidden content
Fixes #14337: Round .jumbotron corners within .container and .container-fluid
Fixes #14329: Fixed list-groups nested inside of collapsing panels, from @apexskier
Undo the collapse visibility changes since it breaks our collapse plugin
Fixes #14439: Add static tooltip example to docs