This patch adds support to the nsxadmin util tool to update
the resource pool ID property for all edges. The resource pool ID
is picked up from the nsx.ini file and updated for all edges in the
backend.
Additionally fix some rendering for admin util.rst
Usage:
nsxadmin -r edges -o nsx-update-all -p appliances=True
Change-Id: I1f4e3137775aefd043da8dda2cd457a4d1f11bf7
feb3ce9ee8