_BSD_SOURCE has been deprecated (see bug). The manpage for printf
suggests that any _POSIX_C_SOURCE >= 200112L is also sufficient to bring
in the needed declarations and the bug reporter confirms that it's
sufficient for him.

https://code.google.com/p/chromium/issues/detail?id=419859

Change-Id: Ifc053f11c5aa1df35aae8e952d2c73a7f4599ec2
Reviewed-on: https://boringssl-review.googlesource.com/1890
Reviewed-by: Adam Langley <agl@google.com>

vsnprintf returns -1 on Windows on truncation, not the needed
size.

Change-Id: I0a9f32504127b2fb740244c3b59132e201d14234
Reviewed-on: https://boringssl-review.googlesource.com/1870
Reviewed-by: Adam Langley <agl@google.com>

A single va_list may not be used twice. Nothing calls BIO_vprintf and it just
(v)snprintfs into a buffer anyway, so remove it. If it's actually needed, we
can fiddle with va_copy and the lack of it in C89 later, but anything that
actually cares can just assemble the output externally.

Add a test in bio_test.c.

BUG=399546

Change-Id: Ia40a68b31cb5984d817e9c55351f49d9d6c964c1
Reviewed-on: https://boringssl-review.googlesource.com/1391
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.)