[c-nsp] ip tcp adjust-mss

[Jean-Francois.TremblayING at videotron.com]

> On ASR1k the MSS adjustment is done on the QFP (the ESP or "in 
hardware").
> Again, this behavior varies from platform to platform.

Note: IPv4 only, for now. IPv6 may be in 15.4(1)S.
See http://www.gossamer-threads.com/lists/nsp/ipv6/45433

/JF