Unbundle jquery from horizon using xstatic

Instead of bundling the jquery.js code with horizon,
we use the xstatic and xstatic-jquery s dependencies
that provide us with the packaged files.

This patch partially implements blueprint remove-javascript-bundling
Further patches will follow.

Change-Id: I395f1c64f2341d4d6847d4f7e648d6c03eb85988
Merge "Unbundle jquery from horizon using xstatic"