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

examples/ostest: Add tests for pthread_rwlock.  Adding tests to be used to verify the pthread_rwlock lock works

Set the 'exit on error control' and/or 'print a trace' of commands when parsing scripts in NSH.  The settinngs are in effect from the point of exection, until they are changed again, or in the case of the init script, the settings are returned to the default settings when it exits.

Included child scripts will run with the parents settings and changes made in the child script will effect the parent on return.

Use 'set -e' to enable and 'set +e' to disable (ignore) the exit condition on commands. The default is -e. Errors cause script to exit.

Use 'set -x' to enable and 'set +x' to disable (silence) printing a trace of the script commands as they are ececuted. The default is +x. No printing of a trace of script commands as they are executed.

examples/nettest:  If doing loopback, but not using the official loopback device, then use the server should use the configured client IP address

NSH: Fix some warnings about integer/pointer casts of different sizes (probably only effects 64-bit simulation)

Causes build problems and does not follow the coding style.

This reverts commit 87fe31f8.

Merged in david_s5/apps-1/david_s5/appsmm-removed-extraneous-comment-from-m-1490711722259 (pull request #71)

apps/mm removed extraneous comment from Makefile

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

built-in libc defect workaround: replace '%6.6u' format with an equivalent '%06u'

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

Adds a test program for the XBox One controller driver (xbc_test).

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

netutils/netlib:  Add one wireless IOCTL wrapper.  For now, this is just a test to be sure that the wireless IOCTL definitions are in place.

apps/examples/usbterm:  Removed because it is not very useful and because it can be configured to use an illegal call into the OS.

apps/examples/hidkbd:  Remove call to arch_usbhost_initialize().  That is violation of the OS interfacing rules and will no longer be supported.  USB host should be initialized as part of the normal board bring-up logic as with any other devices and should not involve illegal calls from applications into the OS.

Add missed dependency

Approved-by: Gregory Nutt

NSH library: In nsh_argexand(), if CONFIG_NSH_ARGCAT is defined but CONFIG_NSH_CMDPARMS defined and/or CONFIG_DISABLE_ENVIRON not defined, then there is a situation that causes an infinite loop in the parser.  Noted by Freddie Chopin.