nova should provide a nova-compute-minimal (or similar)package

Currently, most/all nova-compute-* packages are tied to a specific hypervisor, usually associated with libvirt. As a result, you cannot install a bare minim nova-compute service that does not pull in a ton of dependencies. If a user wishes to run nova-compute using one of the drivers that directly offloads compute tasks to an external resource (VMware, oVirt, etc), they'll install 'nova-compute' (and libvirt-bin, qemu-kvm, etc.) I propose it would make sense to include a package (nova-compute-minimal?) that depends on nova-common + python-nova and installs only the minimum, eg: an upstart job and an empty /etc/nova/nova-compute.conf.