Merge branch 'iplink-parse' into iproute2-next

Serhey Popovych  says:

====================

This is main routine to parse ip-link(8) configuration parameters.

Move all code related to command line parsing and validation to it from
iptables_modify(). As benefit we reduce number of arguments as well as
checking for most of weired cases in single place to give benefit to
iptables_parse() users.

See individual patch description message for more information.

v4
  Drop patches intended to reduce number of arguments to
  iptables_parse(): postpone to the series with real use cases.

  Save only ifi_index in iplink_vxcan.c and link_veth.c: no need
  to save whole ifinfomsg data structure.

  Note that there is no sense to introduce custom version of
  iplink_parse() to use in iplink_vxcan.c and link_veth.c because
  there is too much parameters we need to support (except VF and
  few others) making huge code duplication.

v3
  Move vxlan/veth ifinfomsg save/restore to separate patch to
  make clear change that perform most of request buffer setups
  and checks in iplink_parse().

  Update commit message descriptions and extra new line from
  "utils: Introduce and use nodev() helper routine" patch.

v2
  Terminate via exit() when failing to parse command line arguments
  to help identify failing line in batch mode.

====================

Signed-off-by: David Ahern <dsahern@gmail.com>