Guided option parser

[Jan Engelhardt <jengelh@medozas.de>]

This is a staggered submit, with 10 patches in the first submission.
See 01/10 for a description.

Currently, the entire set of 64 has a diffstat of

 74 files changed, 2845 insertions(+), 4062 deletions(-)

this is roughly a third of the entire work, and it is expected this
to linearly continue until ~200 patches. But I felt I needed to flush
the queue now.

===
The following changes since commit a239728ec064666025de2723997d87b176d57fd6:

  mark newly opened fds as FD_CLOEXEC (close on exec) (2011-04-04 15:30:32 +0200)

are available in the git repository at:
  git://dev.medozas.de/iptables opts

Jan Engelhardt (10):
      extensions: add missing checks for specific flags (2)
      libxtables: guided option parser
      libxt_CHECKSUM: use guided option parser
      libxt_socket: use guided option parser
      libxtables: provide better final_check
      libxt_CONNSECMARK: use guided option parser
      libxtables: XTTYPE_UINT32 support
      libxt_cpu: use guided option parser
      libxtables: min-max option support
      libxt_cluster: use guided option parser

 Makefile.am                     |    2 +-
 extensions/libip6t_ipv6header.c |    4 +-
 extensions/libxt_CHECKSUM.c     |   46 ++----
 extensions/libxt_CONNSECMARK.c  |   59 +++----
 extensions/libxt_cluster.c      |  187 +++++---------------
 extensions/libxt_cpu.c          |   65 ++-----
 extensions/libxt_socket.c       |   29 ++--
 include/xtables.h.in            |  111 ++++++++++++
 ip6tables.c                     |   56 ++++--
 iptables.c                      |   58 ++++---
 xshared.h                       |   20 ++
 xtables.c                       |   25 +--
 xtoptions.c                     |  366 +++++++++++++++++++++++++++++++++++++++
 13 files changed, 695 insertions(+), 333 deletions(-)
 create mode 100644 xtoptions.c