According to the code, 'virsh numatune' supports integers for
specifying --mode as well as the string definitions "strict",
"interleave", and "preferred".  However, this possibility was not
documented anywhere, so this patch adds it to both the man page and
command help.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1085706Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>