Reverting bridge/antispoofing param removal

[Nivedita Singhvi <niv@us.ibm.com>]

While cleaning up some other stuff in this area, I looked
into a problem Sean Dague ran into - he was specifying br0
as the bridge name in xend-config.spx and it was still using
the original default xenbr0.  When the bridge name is
specified in the network-bridge script, it is created
correctly (ditto anti-spoofing).

A recent patchset:
http://lists.xensource.com/archives/html/xen-changelog/2005-10/msg00305.html

removed the parameters vif-bridge and anti-spoofing from
the xend/vifctl.py as the script was allowing them
to be configured.

The config file still has the examples, however, which
results in the user setting those parameters in
xend-config.spx futilely.  The actual parameter that is
used is the default (unless overridden in the script).
The intent seems to be to allow the user to configure
it in the script, and avoid the redundancy of overriding
via xend.

Would you rather have a patch that removes the example
from the xend-config.spx script, so as not to confuse the
user (but this would need sanitizing xend to use the right
params) or restore the original piece of code? It latter
worked well before, you could set it in one place and
have it be seen by script and xend.

I had both in test, will send off whichever is
desirable when I get in tmrw..

thanks,
Nivedita