Rename Tags -> Keywords on package create/edit forms
More dataset and resource form simplification

Including changing from three- to two-stage dataset creation.

Move version from third to first stage of new package forms.

Remove description from new/edit resource form.

Change three-stage dataset creation to two.

Change "Next: Additional metadata" button to "Finish".

Add fanstatic dir containing custom CSS file, with some CSS tweaks needed for
the two-stage form.

Reroute /dataset/new_metadata/{id} to new B2PackageController which changes
the package state to active and then redirects you to the package read page.
Hide some more fields on the package edit form