Add xstatic-packaged JavaScript libraries for Horizon

Those libraries are removed from Horizon's static directory, and
packaged separately for easier maintenance and versioning.

They package sources are going to be hosted on StackForge, see
patch https://review.openstack.org/#/c/95716/

Change-Id: I3efd9527d9be8c263458d0531f7a4c9c49d75d01
Partially-implements: blueprint remove-javascript-bundling
Add new library oslo.utils

Add the new library oslo.utils so projects can start adopting it.

Change-Id: I9e61adfac71f159e3a6aa77cbcbb26279dc42869
Merge "Add xstatic-packaged JavaScript libraries for Horizon"
Merge "Add new library oslo.utils"