This commit stops using deprecated WSA functions. While the ANSI
versions are most likely not going anywhere, Windows is natively UTF-16
so it has to convert to ANSI internally. All the ANSI functions in
Winsock are marked as deprecated. The macro suppressing the warnings is
no longer defined.
SocketAddressWindows.h contains a bunch of copy-pasted Windows
definitions. This started causing ad-nauseam redefinition errors when
implementing the HTTP disk cache for Windows.
Instead, let's forward-declare the types we can in SocketAddress.h and
only define the couple of constants that we need. We can then assert at
compile-time that we defined them correctly.