removed outline from modal
Customizable backdrop opacity
Added opacity to customizer and rebuilt customizer
Options of sizes added in modal
Adjust in modal size rules
Add well-border variable

Add a variable to allow the well border color to be specified.

The reason I'd like to see this included is that my companies styleguide
requires an explicit border color on well-like constructs. This variable
allows me to easily override the default to use that color.
Fix #11400 and #11431
Reduce size of the visibility styles
Add `.animation-*()` mixins
Remove unused variables.
transform origin mixin for explorer
Sauce tests: update to later browsers supported by OS X 10.9
Merge pull request #11863 from twbs/update-osx

Sauce tests: update to later browsers supported by OS X 10.9
Merge pull request #11819 from janpanschab/ms-transform-origin

Transform-origin mixin for IE
-ms-transform is for IE9 only, IE10+ don't require it
use @zindex-modal for .modal and @zindex-modal-background for .modal-backdrop.
removed z-index for .modal-dialog, it was not necessary because the parent element (.modal) already has a z-index.
add dist files.
';' isn't needed
Merge pull request #11874 from ZDroid/hotfix

';' isn't needed
use S3-based node_modules caching