cleanup admin-guide architecture
cleanup admin-guide architecture

- remove reference to api
- remove dup details on compute, central, ipmi already in data
collection
- remove hbase from panko support
- remove listing libvirt hypervisors, we only test kvm/qemu.
- remove generic listing of 'OpenStack Networking' meters. we already
have a measurements page for this
- remove user, roles, projects notes. we don't have api and it
means very little as is

Change-Id: I292cdd9297549ab8cb78caf6b15941b3986ca898

openstack/ceilometer,openstack/ceilometer