* src/proxy_internal.c, src/proxy_internal.h,
	  src.xen_internal.c, src/xen_internal.h,
	  src/xen_unified.c, src/xen_unified.h,
	  src/xend_internal.c, src/xend_internal.h,
	  src/xm_internal.c, src/xm_internal.h,
	  src/xs_internal.c, src/xs_internal.h: The interface
	  between xen_unified.c and its underlying driver now uses
	  a custom structure (struct xenUnifiedDriver) instead
	  of reusing virDriver.
	* src/xen_unified.c: virDomainLookup* functions in Xen
	  now throw VIR_ERR_NO_DOMAIN if the domain does not exist.
	* src/xs_internal.c: Fix indentation.