As soon as the NIC is plugged, unpause the domain and exit

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
libxc: skip a pointless madvise() call

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
xl: remove file lock

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
libxenstore: throw away error responses to allow write pipelining

In particular this should speed up code which does
  write k = v
  write k = v
  ...
  write k = v
because all the 'write k' requests will be sent without waiting for
the 'unit' results to come back.

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Avoid the vif hotplug script by using ioctl()

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Parallelise vif hotplug with domain build

We add the xenstore tree before we kick off the domain builder
so both happen in parallel. We still synchronise with the hotplug
at the end but we can usually avoid xenstore watches since the
hotplug has usually completed already.

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Don't add a console to save time

This isn't strictly needed, although it makes guest debugging
difficult.

Signed-off-by: David Scott <dave.scott@eu.citrix.com>