* Rename bundles (prep for webpack optimisation)
This might or might not reduce the overall repo size,
because git can combine similar chunks in the newly generated files
* Optimise webpack build time
Consolidates bundles, since a separation of bundle-framework.js vs. bundle-legacy.js
vs. bundle-lib.js no longer makes sense - they're all loaded upfront anyway,
since we'll be introducing more react-powered logic alongside the "legacy" JavaScript.
By consolidating into fewer bundles, we give the optimisation scripts (UglifyJS)
more options to reduce the overall file size.
The main motivation for a vendor.js is to shorten rebuild times:
Most active development is happening in files required through bundle.js.
This commit drastically reduces the rebuild time for those changes (15s to 4s).
Used in iframe, so can't be rolled into other code.
Moved in admin/ since that's easier for now with Webpack entry points,
and we'll move all JS/CSS into admin/ anyway soon.
