NetLib:

NetLib:
1. Add new interface Ip6IsValidUnicast
2. Add new enum IP6_EXTENSION_HEADER_TYPE
3. Add new structure IP6_ICMP_* definitions
4. Update structure from EFI_UDP4_HEADER to EFI_UDP_HEADER
5. Add new macro EFI_IP6_EQUAL

IpIoLib:
1. Update the IpIoLib to a combined library for both v4 and v6 network stack
2. Fix a bug in IpIoIcmpHandler() - for IPv6 packet, the header length is variable (basic header + extension) rathar than fixed length.
   The fix removes the IPv6 header fields and notify the user with the ICMPv6 packet only containing payload.

TcpDxe/UdpDxe:
1. Update to adapt the new combined IpIoLib
2. Add gEfiIp6ProtocolGuid/gEfiIp6ServiceBindingProtocolGuid to [Protocols] in INF file since the Ip6.h is included in IpIoLib and NetLib.
3. Pass the TCP4/UDP4 UEFI SCT test on NT32 platform.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9374 6f19259b-4bc3-4df7-8a09-765794883524