Squashed commit of the following:

    Merged in merlin17/apps/i8sak-sock (pull request #108)

    i8sak: Fixes mistake where socket was accidentally bound to endpoint address
    i8sak: Fixes bad logic that bound outbound port to the destination address
    i8sak: Adds sniffer port option and a few other get/set parameters

    Merged in merlin17/apps/i8sak-sock (pull request #106)

    i8sak: Endpoint address is updated whenever 802.15.4 addressing information is updated
    wireless/ieee802154/i8sak: Converts PF_INETX to PF_INET6 and SOCK_IWPAN to SOCK_DGRAM
    wireless/ieee802154/i8sak: Catches case where arguments are included,  but the interface was never set
    wireless/ieee802154/i8sak: Endpoint IP address is now updated whenever 802.15.4 addressing info changes
    wireless/ieee802154/i8sak: Routes all error output to stderr rather than stdout

    Merged in merlin17/apps/i8sak-sock (pull request #104)

    i8sak: Fixes socket version of sniffer logic. socket logic for sniffer now works
    i8sak: Fixes socket version of sniffer logic. socket logic for sniffer now works

    Merged in merlin17/apps/i8sak-sock (pull request #103)

    wireless/ieee802154/i8sak: Adds socket interface support. You can now use both socket or char driver to control the MAC layer

    * wireless/ieee802154: Removes useless wpanlistener folder with build files
    * wireless/ieee802154/libmac: Merges some files together and adds some missing sixlowpan functionality
    * wireless/ieee802154/i8sak: Starts adding support for both character driver and socket
    * Removes unneccessary Kconfig statement
    * ieee802154: Adds function prototypes missed on previous commit
    * wireless/ieee802154/libmac: Fixes sixlowpan_resetreq
    * wireless/ieee802154/libmac: Small fixes and removes enableevents helper
    * apps/ieee802154/i8sak: Moves wpanlistener functionality into i8sak directly
    * apps/ieee802154/i8sak: Major restructuring to allow both char driver and socket control

        Also changes Kconfig options and certain args held previously by i8sak. This is to bring it closer to a real CLI tool rather than a development tool. For instance, no longer does the app change the addressing of the device automatically. This is because you probably don't want i8sak overwriting the extended address after board bring-up.  Additionally, the endpoint logic has been simplified.  There is only ever one active endpoint now.

    * wireless/ieee802154/i8sak: Non-functional clean-up.
    * i8sak: Removes chan and coordinfo commands and introduces generic get/set commands
    * i8sak: startpan now requires PAN ID argument
    * i8sak: Adds ability to set endpoint address using set command
    * i8sak: Minor fixes and cleanup
    * i8sak: Adds addrmode setting to i8sak. exposed via get/set calls
    * i8sak: Clean up poll logic and allow polling address mode to be based off endpoint address setting.
    * i8sak: Trivial
    * i8sak: Adds get/set hook for endpoint address mode (destination address mode)
    * i8sak:  Changes default address modes to short.
    * i8sak: Fixes build erros associated with enabling 6LoWPAN support
    * i8sak: Adds socket version of get/set implementation.  Simplifies some logic as well.
    * wireless/ieee802154/i8sak: Removes unused files
    * wireless/ieee802154/libmac: Fixes sixlowpan_assocresp.  resp was not being copied into the ioctl argument.

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