Networking:  Clean up some naming that has bothered me for a long time... There are no interrupts and no interrupt handlers in the network.  There are events and event handler (there used to to be interrupt logic in there years ago but that is long, long gone).

6LoWPAN/PF_IEEE802154:  Created radiodev.h and renamed various structures to provide a better separation between 6LoWPAN and PF_IEEE802154.

commit 2a3ab1652a2c95bcfc8be8380fc7cbdcb6472938
Author: Gregory Nutt <gnutt@nuttx.org>
Date:   Sat Aug 19 08:44:31 2017 -0600

    PF_IEEE802154: Finish some missing bind() logic.  Add configs/sim configuration for testing.

commit 59be4b846a6e3bfe82087a888e3fdac9c3c414e5
Author: Gregory Nutt <gnutt@nuttx.org>
Date:   Fri Aug 18 19:30:04 2017 -0600

    PF_IEEE802154:  More renaming to decouple 6LoPAN from radios in general.

commit 69fabb1aea76e54381bdc13de28a3f1441fb42f4
Author: Gregory Nutt <gnutt@nuttx.org>
Date:   Fri Aug 18 19:21:11 2017 -0600

    PF_IEEE802154: Missed a few renamings.

commit ff0af1bb25567720934cc1c2a721ccd92cc35f89
Author: Gregory Nutt <gnutt@nuttx.org>
Date:   Fri Aug 18 17:46:58 2017 -0600

    PF_IEEE802154:  A few bugfixes

commit 01c7c84afd00cf907d280d30cfaf0fb2cf90e02e
Author: Gregory Nutt <gnutt@nuttx.org>
Date:   Fri Aug 18 17:01:31 2017 -0600

    PF_IEEE802154:  A few bugfixes

commit dcef4056d1c1488c93151135f3b7106977faa903
Author: Gre...

Networking:  When sending ICMPv6 advertisements and solicitations, set the NOARP bit so that we don't overwrite the destination MAC address

Networking:  Replace all references to net_ipaddr_t with either in_addr_t on net_ipv6addr_t.  The goal is to support both IPv4 and IPv6 simultaneously.  This requires that the two types be distinct and not conditionally typedef'ed to net_ipaddr_t.

PKT sockets: Change how the IFF_NOARP flag is handled.  This should be set only when data is moved into the buffer and cleared after tested by the ARP logic.  Setting it globally can cause packets to be sent with no valid MAC addresses

NET: emoved all includes of uip.h; added includes of ip.h wherever needed.  Tried to fix problems of the now missing sneak inclusions because uip.h was removed.  There are probably a few of these that were missed.

Move the remaining files from include/nuttx/net/uip to include/nuttx/net; Rename *_internal.h header files in net/ to just *.h

Separate net/net_send_buffered.c and net/net_send_unbuffered.c to net/tcp/tcp_send_buffered.c, net/tcp/tcp_send_unbuffered.c, and pkt/pkt_send.c