use wrapShim flag to fix dependence of a shim (backbone.paginator) on an AMD module (backbone)

See https://github.com/jrburke/r.js/issues/623 for more info

Without this we were getting "Uncaught ReferenceError: Backbone is not defined" errors in the plone bundle
Merge pull request #349 from plone/davisagli-wrapShim

use wrapShim flag to fix dependence of a shim (backbone.paginator) on an...