Define WIN32_LEAN_AND_MEAN before including Windows Platform SDK
headers to preempt naming conflicts and to make the build faster. Avoid
including those headers in BoringSSL headers. Document that Platform
SDK 8.1 or later is required on Windows.

Change-Id: I907ada21dc722527ea37e839c71c5157455a7003
Reviewed-on: https://boringssl-review.googlesource.com/3100
Reviewed-by: Adam Langley <agl@google.com>

Otherwise, in C, it becomes a K&R function declaration which doesn't actually
type-check the number of arguments.

Change-Id: I0731a9fefca46fb1c266bfb1c33d464cf451a22e
Reviewed-on: https://boringssl-review.googlesource.com/1582
Reviewed-by: Adam Langley <agl@google.com>

Windows doesn't have ssize_t, sadly. There's SSIZE_T, but defining an
OPENSSL_SSIZE_T seems worse than just using an int.

Change-Id: I09bb5aa03f96da78b619e551f92ed52ce24d9f3f
Reviewed-on: https://boringssl-review.googlesource.com/1352
Reviewed-by: Adam Langley <agl@google.com>

On OS X, the length must be the length of the address and not of
sockaddr_storage.

Change-Id: Id962f2f3268f07327724b9867a83c15ec50cb9fd
Reviewed-on: https://boringssl-review.googlesource.com/1251
Reviewed-by: Adam Langley <agl@google.com>

PNaCl needs OPENSSL_NO_ASM to work and a couple of cases were missing
because it hasn't previously been tested.

Additionally, it defined _BSD_SOURCE and others on the command line,
causing duplicate definition errors when defined in source code.

It's missing readdir_r.

It uses newlib, which appears to use u_short in socket.h without ever
defining it.

Change-Id: Ieccfc7365723d0521f6327eebe9f44a2afc57406
Reviewed-on: https://boringssl-review.googlesource.com/1140
Reviewed-by: Adam Langley <agl@google.com>

Initial fork from f2d678e6e8 (1.0.2 beta).

(This change contains substantial changes from the original and
effectively starts a new history.)