allow require.resolve('bootstrap') to work under node
added 'main' field to package.json
added a separate npm-specific main file
generate commonjs/npm entrypoint module via grunt task
Merge remote-tracking branch 'upstream/master' into node-requirable

Conflicts:
	Gruntfile.js
pulled output path out to gruntfile
code style fixes
added banner about generated file
code style improvement
Use e.target instead :focus selector.
Only enable `pause: hover` for non-touch browsers

Fixes #11967.
Fix #12563: Reiterate that empty tooltips+popovers do not get displayed
Merge pull request #14716 from blankmaker/docs/fix-12563

Fix #12563: Elaborate that popover('show') checks title/content
Merge pull request #14626 from twbs/carousel-pause-hover-non-mobile

Only enable `pause: hover` for non-touch browsers
fixes #14714: don't use specific value in buttons docs
Merge branch 'master' of github.com:twbs/bootstrap
Add `keyboard` option to carousel

Also adds unit tests for keyboard events.

Fixes #14468.
grunt
Escape key should only close Dropdown
Fixes #14711: Account for list groups in collapsing panels