- Copy net/devif/devif_input.c to ipv6_input.c.  Remove all IPv4-specific logic.
- Rename net/devif/devif_input.c to ipv4_input.c.  Remove all IPv6-specific logic
- Split IPv4 header structure out as net_ipv4hdr_s from net_iphdr_s

Networking:  (1) Copied all ICMP sources files to net/icmpv6 with proper renaming and removal of IPv4 logic, (2) remove IPv6 logic from files in net/icmp, (3) copied include/nuttx/icmp.h to icmpv6.h and removed IPv4 specific logic, (4) removed all IPv6 logic from icmp.h, (5) IP_HDRLEN became IPv4_HDRLEN and IPv6_HDRLEN, (6) ip_chksum() became ipv4_chksum() and ipv6_chksum(), and (7) added partial support for ICMPv6 statistics.

Network:  All logic will now handle varialbe length link layer protocol headers within incoming packets.  This permits use of multiple network interfaces with differing data links.  For example, ETHERNET + SLIP

Netwoek:  Ada a parameter to netdev_register() to indicate the link protocol supported by the driver.  Use this value to replace some logic commited yesterday

Finishes the ioctl definition to subscribe to PHY events. Revamp network ioctl signature to support arguments other than struct mii_ioctl_data.

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.

Add support for a network device IOCTL to access PHY registers.  Ioctls only implemented for STM32.  From Lazlo

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

Move include/nuttx/net/uip/uip-arch.h to include/nuttx/net/arp.h; rename all uip_arp_ functions to arp_

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5308 42af7a65-404d-4744-a932-0658087f49c3

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4450 42af7a65-404d-4744-a932-0658087f49c3

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3674 42af7a65-404d-4744-a932-0658087f49c3

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3376 42af7a65-404d-4744-a932-0658087f49c3