vmm/kvm: Work with KVM shipped with RHEL 5.4
vmm/kvm: Work with KVM shipped with RHEL 5.4

- RHEL 5 puts KVM in /usr/libexec for some reason.  Include that
directory in the KVM search path.

- Loosen version-detection regexp to match KVM version strings like
"kvm-83-maint-snapshot-20090205"

cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr