[Change summary]:

[Change summary]:
1. Update NetLib to a combined NetLib support dual network stack:
1) Add Network Debug facility for IPv4 stack.
2) Extend the library APIs to support IPv6 stack:
   a. NetIp6IsUnspecifiedAddr
   b. NetIp6IsLinkLocalAddr
   c. NetIp6IsNetEqual
   d. NetLibCreateIPv6DPathNode.
   e. NetIp6PseudoHeadChecksum
   f. NetIp6IsValidUnicast
3) Update the structure definitions:
   a. Update NET_BUF to add EFI_IP6_HEADER and EFI_UDP_HEADER
   b. Add NET_IP6_PSEUDO_HDR
4) Update Ip4IsUnicast to NetIp4IsUnicast

2. Update the impacted modules to adopt the combined NetLib.

3. Clean up coding style errors in all network drivers and libraries.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9391 6f19259b-4bc3-4df7-8a09-765794883524