wireless/ieee802154: Starts framing out iwpan tool, similar in concept to wapi

Approved-by: Gregory Nutt <gnutt@nuttx.org>

NSH library: Fix open flags in nsh_codeccmd.c

Approved-by: Gregory Nutt <gnutt@nuttx.org>

Jira: PDFW15IS-2824
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

wireless/wapi:  Remove functionality that depends on the Linux procfs:  This includes only 1) listing of available interfaces and 2) listing of all routes.

apps/wireless/wapi:  Fix problems in build support.  Fix some initial compile isses (still does not compile).

wireless/wapi:  Quick port of Wapi wireless services.  No build support yet.  This also depends on features not supported by NuttX.  This is a work in progress.

pthreads:  Backed most of last pthread changes.  Found the 'real' root poblem.  A one like error in pthread_mutex.c.

examples/ostest:  pthread clean-up test must call pthread_consistent, not pthread_mutex_unlock() on cancellation if robust mutexes are enabled.

NSH library: Extend ifconfig to support 6loWPAN.  Adapt to some changes in configuration variable usage.