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>

This exposes the features needed to mimic Chrome's ClientHello, which is useful
in testing. Also use bssl_shim's scopers for SSL objects.

Change-Id: Icb88bb00c0a05c27610134d618f466a24f7f757a
Reviewed-on: https://boringssl-review.googlesource.com/4113
Reviewed-by: Adam Langley <agl@google.com>

Change-Id: Iea9bd25176724b56ebb21bded6925f5d30176548
Reviewed-on: https://boringssl-review.googlesource.com/3071
Reviewed-by: Adam Langley <agl@google.com>

Change-Id: Ia8588aeaad8b44a6a306d7d5bfecc895adde1910