[Libvir] Fedora spec file changes

[Mark McLoughlin]

Hey,
	First thing - libvirt.spec has previously matched the spec file we've
used in Fedora for building packages, but now it's quite a bit out of
sync.

	My question is whether libvirt.spec should be upstream at all:

  1) Having the two copies is confusing - which is canonical?

  2) Keeping the two copies in sync is time consuming, especially if 
     they're not going to be exactly identical.

  3) It's not clear that it's useful to have it upstream at all - i.e. 
     is it useful anywhere but Fedora? Are iscsi-initiator-utils or 
     selinux-devel valid RPM names on any other distro?

  4) If we're to keep libvirt.spec in CVS purely as a convenience for
     Fedora users wanting to build the latest tarball, then we should 
     be ensuring that libvirt.spec is usable for the tarball *before* 
     releasing it, which is a pain.

	Personally, I think we should remove it from upstream libvirt.

	Finally, here's some changes to how arch conditionals are handed in the
spec file - what prompted this was the way we were enabling with_proxy
even when with_xen was disabled, causing the proxy to be in the files
section even when it wasn't built. Please give it a look over before I
built in dist-f10.

Cheers,
Mark.