New bird functionality

[Thierry FOURNIER]

Hello,

I submit two patched.

   0001-PATCH-FLX-Add-command-line-option-for-specifying-the.patch

The first one is to add the -P <pidfile> argument on the command line.
On some distributions, the pidfile is managed into the start script and
not into the configuration file.

   0003-FEAT-Add-protocol-volatile.patch

The second patch is new protocol. I named it "protocol volatile". This
permit to add routes into bird via the control socket. These route are
volatile: when bird restart, they are lost.

This is useful for servers using transparent redirect and transparent
binding like "squid" or "haproxy". This two softs can receive trafic for
an ip not present on the system. This new feature "protocol volatile"
permit to do high avalaibility infrastructure with announcing these
routes only if the service is avalaible. This permit also to do
load-balacing: if many computers annouce the same route, the router can
be use ecmp algorithm for the repartion.

Thierry FOURNIER