Finish up crypto, minus the legacy modules we haven't been touching much.

Change-Id: I0e9e1999a627aed5fb14841f8a2a7d0b68398e85
Reviewed-on: https://boringssl-review.googlesource.com/4517
Reviewed-by: Adam Langley <agl@google.com>

This introduces a per-RSA/DSA/DH lock. This is good for lock contention,
although pthread locks are depressingly bloated.

Change-Id: I07c4d1606fc35135fc141ebe6ba904a28c8f8a0c
Reviewed-on: https://boringssl-review.googlesource.com/4324
Reviewed-by: Adam Langley <agl@google.com>

Beyond generally eliminating unnecessary includes, eliminate as many
includes of headers that declare/define particularly error-prone
functionality like strlen, malloc, and free. crypto/err/internal.h was
added to remove the dependency on openssl/thread.h from the public
openssl/err.h header. The include of <stdlib.h> in openssl/mem.h was
retained since it defines OPENSSL_malloc and friends as macros around
the stdlib.h functions. The public x509.h, x509v3.h, and ssl.h headers
were not changed in order to minimize breakage of source compatibility
with external code.

Change-Id: I0d264b73ad0a720587774430b2ab8f8275960329
Reviewed-on: https://boringssl-review.googlesource.com/4220
Reviewed-by: Adam Langley <agl@google.com>

Now that ERR is using thread-local storage, there's very little that the
THREADID code is doing and it can be turned into stub functions.

Change-Id: I668613fec39b26c894d029b10a8173c3055f6019

Everything else.

Change-Id: Iac02b144465b4e7b6d69ea22ff2aaf52695ae732

Including string.h in base.h causes any file that includes a BoringSSL
header to include string.h. Generally this wouldn't be a problem,
although string.h might slow down the compile if it wasn't otherwise
needed. However, it also causes problems for ipsec-tools in Android
because OpenSSL didn't have this behaviour.

This change removes string.h from base.h and, instead, adds it to each
.c file that requires it.

Change-Id: I5968e50b0e230fd3adf9b72dd2836e6f52d6fb37
Reviewed-on: https://boringssl-review.googlesource.com/3200
Reviewed-by: David Benjamin <davidben@chromium.org>
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.)