Parse cookie pair extended option (previously defined).

Define and parse 64-bit timestamp extended option (and minor cleanup).
However, only 32-bits are used at this time (permitted by specification).

Every bit is sacred.  Use as few bits as possible in the tcp_sock
structure, at the expense of performance.

Requires:
   net: tcp_header_len_th and tcp_option_len_th
   TCPCT part 2f: cleanup tcp_parse_options

Signed-off-by: William.Allen.Simpson@gmail.com
---
  include/linux/tcp.h  |   10 ++++-
  include/net/tcp.h    |   45 ++++++++++---------
  net/ipv4/tcp_input.c |  119 ++++++++++++++++++++++++++++++++++++++++++++++----
  3 files changed, 142 insertions(+), 32 deletions(-)