This change converts the reference counts in crypto/ to use
|CRYPTO_refcount_t|. The reference counts in |X509_PKEY| and |X509_INFO|
were never actually used and so were dropped.

Change-Id: I75d572cdac1f8c1083c482e29c9519282d7fd16c
Reviewed-on: https://boringssl-review.googlesource.com/4772
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>

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>

One of them was never implemented upstream or downstream. The other no longer
works in BoringSSL. They're not used within BoringSSL (this still compiles),
even in X509_INFO, and do not appear to be used by consumers. If they were, we
would like to know via a compile failure.

This removes the last consumer within BoringSSL of the ASN.1 parsing macros.

Change-Id: Ifb72b1fcd0a4f7b3e6b081486f8638110872334b
Reviewed-on: https://boringssl-review.googlesource.com/2203
Reviewed-by: Adam Langley <agl@google.com>

Caught by clang scan-build.

Change-Id: I075ae0423ec72493f21608ab5704e2984ca3e86c
Reviewed-on: https://boringssl-review.googlesource.com/2202
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.)