#3192: First pass on RESTws plugin for vsites.
#3192: Implement most of vsite create.
#3192: Implement menu entry to get purls.
#3192: Remove the vsite REST resource.
#3192: Remove references to rest requests in vsite_register.
#3192: One more reference.
Merge pull request #3250 from openscholar/3192-vsite_register_rest_apis

Request to get all site's PURLs