* include/libvirt.h[.in] include/virterror.h src/driver.h

* include/libvirt.h[.in] include/virterror.h src/driver.h
  src/internal.h src/libvirt_sym.version src/xen_internal.c
  src/xs_internal.c: added a new entry point to get node hardware
  informations virGetNodeInfo, and associated driver hook.
* src/xend_internal.c: implemented the node and version information
  hooks for the Xen Daemon
* python/libvir.c python/libvirt-python-api.xml python/generator.py:
  also added Python bindings for the new call
Daniel