Fix qemu media connect/eject to work with latest syntax. Add support for ejecting floppy devices and scsi cdroms.

* src/domain_conf.c src/domain_conf.h src/qemu_conf.c
  src/qemu_driver.c: patch from Guido Günther allowing to add
  disk as USB devices
* docs/libvirt.rng: extend the schemas for the new value
* tests/qemuxml2argvdata/qemuxml2argv-disk-usb.args
  tests/qemuxml2argvdata/qemuxml2argv-disk-usb.xml
  tests/qemuxml2argvtest.c tests/qemuxml2xmltest.c: add a specific
  test to the regression suite
Daniel

* src/domain_conf.c src/domain_conf.h src/qemu_conf.c
  src/qemu_driver.c: Patch from Guido Günther allowing to pass
  usb devices to qemu/kvm
* docs/libvirt.rng: add the new functionality to the grammar
* tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address.args
  tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address.xml
  tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-product.args
  tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-product.xml
  tests/qemuxml2argvtest.c tests/qemuxml2xmltest.c: adding examples
  to the regression tests
* libvirt.spec.in: fix the licence tag
Daniel

* src/domain_conf.[ch] src/openvz_conf.[ch] src/openvz_driver.c:
  patch from Evgeniy Sokolov doing the OpenVZ xml refactoring,
  still needs to be ported to the new XML parsing code but
  implements the new format.
Daniel