doc: Update libvirt-numa guide
doc: Update libvirt-numa guide

Update the documents, making the following changes:

* Reference Fedora 24 instead of the outdated Fedora 21
* Don't reference the removed 'rejoin-stack' script
* Let devstack do as much work for us as possible (NUMATopologyFilter)
* Don't overcomplicate anything (installing emacs, using non-standard
  devstack install dir)
* Use '$' prefix for non-root commands
* Update XML with latest examples
* Use the 'openstack' client, rather than the 'nova' client
* Random formatting fixes

...and, finally, stop hating on poor, innocent vi.

Change-Id: Idc89a5c0617ccf7044e1cfc2b5d7f5ff4004b5bf

rajalokan/nova,mahak/nova,rahulunair/nova,vmturbo/nova,gooddata/openstack-nova,gooddata/openstack-nova,klmitch/nova,jianghuaw/nova,hanlind/nova,rajalokan/nova,jianghuaw/nova,vmturbo/nova,gooddata/openstack-nova,vmturbo/nova,mahak/nova,mikalstill/nova,Juniper/nova,openstack/nova,klmitch/nova,jianghuaw/nova,openstack/nova,mikalstill/nova,jianghuaw/nova,mahak/nova,klmitch/nova,openstack/nova,hanlind/nova,Juniper/nova,klmitch/nova,hanlind/nova,Juniper/nova,vmturbo/nova,phenoxim/nova,gooddata/openstack-nova,mikalstill/nova,Juniper/nova,rajalokan/nova,rahulunair/nova,phenoxim/nova,rahulunair/nova,rajalokan/nova