|SSL_CTX| and |X509_STORE| have grown their own locks. Several static
locks have been added to hack around not being able to use a
|CRYPTO_once_t| in public headers. Lastly, support for calling
|SSL_CTX_set_generate_session_id| concurrently with active connections
has been removed. No other property of an |SSL_CTX| works like that.

Change-Id: Iff5fe3ee3fdd6ea9c9daee96f850b107ad8a6bca
Reviewed-on: https://boringssl-review.googlesource.com/4775
Reviewed-by: Adam Langley <agl@google.com>

Keep internal callers up-to-date with deprecations.

Change-Id: I7ee171afc669592d170f83bd4064857d59332878
Reviewed-on: https://boringssl-review.googlesource.com/4640
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>

Get all this stuff out of the way.

- OPENSSL_NO_MD5
- OPENSSL_NO_SHA
- OPENSSL_NO_EC
- OPENSSL_NO_ECDSA
- OPENSSL_NO_ECDH
- OPENSSL_NO_NEXTPROTONEG
- OPENSSL_NO_DH
- OPENSSL_NO_SSL3
- OPENSSL_NO_RC4
- OPENSSL_NO_RSA

Also manually removed a couple instances of OPENSSL_NO_DSA that seemed to be
confused anyway. Did some minor manual cleanup. (Removed a few now-pointless
'if (0)'s.)

Change-Id: Id540ba97ee22ff2309ab20ceb24c7eabe766d4c4
Reviewed-on: https://boringssl-review.googlesource.com/1662
Reviewed-by: Adam Langley <agl@google.com>

Reference counting should be internal to the type, otherwise callers need to
know which lock to use.

Change-Id: If4d805876a321ef6dece115c805e605584ff311e
Reviewed-on: https://boringssl-review.googlesource.com/1414
Reviewed-by: Adam Langley <agl@google.com>

Building without RSA support is unreasonable. Changes were made by
running

find . -type f -name *.c | xargs unifdef -m -U OPENSSL_NO_RSA
find . -type f -name *.h | xargs unifdef -m -U OPENSSL_NO_RSA

using unifdef 2.10 and some newlines were removed manually.

Change-Id: Iea559e2d4b3d1053f28a4a9cc2f7a3d1f6cabd61
Reviewed-on: https://boringssl-review.googlesource.com/1095
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.)