#46 Update global protocol GUIDs definitions to match EDK2

[Pete Batard]

Update global protocol GUIDs definitions to match EDK2

This patch introduces the use of the EDK2 names for the global GUID variables,
to allow for easier code conversion between EDK2 and gnu-efi. All the existing
GUID global variables have also been aliased for backwards compatibility.

The patch also completes some of the earlier work with regards to protocol
struct definitions to also match the EDK2, with the following caveat:
Because some of gnu-efi GUID macro definitions were declared with the name
that the EDK2 uses for the protocol struct itself, we have to immediately
deprecate the following GUID data aliases:

• EFI_NETWORK_INTERFACE_IDENTIFIER_PROTOCOL
• EFI_SIMPLE_NETWORK_PROTOCOL
• EFI_PCI_IO_PROTOCOL
• EFI_PXE_BASE_CODE_CALLBACK_PROTOCOL
  This means that existing code using one of the above will break on compilation.
  To mitigate this, explicit warnings have been placed at the location where a
  developer will look for breakage, detailing how they should amend their code.

The KnownGuids short labels in guid.c were also updated/amended in a manner
that should be a bit more consistent (though I have no idea what the EDK2
does here, since I haven't looked at the actual EDK2 source).

Finally, besides clean up (typo, whitespaces, duplicate removal), we introduce
the _GNU_EFI macro, in efi.h, to allow for conditional selection of specific
gnu-efi API calls, in code that may be compiled with either EDK2 or gnu-efi.

[Nigel Croxon]

commit 751cbce3f640c79fbb4660cb59a372b79a7f4d11

Thank You Pete !