[Libguestfs] [PATCH FOR DISCUSSION ONLY] availability: Add guestfs_available.

For discussion only. FWIW we have a similar API in libvirt, although in libvirt it's an internal-only API. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones New in Fedora 11: Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 70 libraries supprt'd http://fedoraproject.org/wiki/MinGW http://www.annexia.org/fedora_mingw