gcm_test.cc needs to access the internal GCM symbols. This is
unfortunate because it means that they have to be marked OPENSSL_EXPORT
just for this.

To compensate, modes.h is removed and its contents copied into
crypto/modes/internal.h.

Change-Id: I1777b2ef8afd154c43417137673a28598a7ec30e
Reviewed-on: https://boringssl-review.googlesource.com/6360
Reviewed-by: Adam Langley <alangley@gmail.com>

This removes the confusion about whether |gcm128_context| copies the
key (it didn't) or whether the caller is responsible for keeping the
key alive for the lifetime of the |gcm128_context| (it was).

Change-Id: Ia0ad0a8223e664381fbbfb56570b2545f51cad9f
Reviewed-on: https://boringssl-review.googlesource.com/6053
Reviewed-by: Adam Langley <alangley@gmail.com>

The key is never modified through the key pointer member, and the
calling code relies on that fact for maintaining its own
const-correctness.

Change-Id: I63946451aa7c400cd127895a61c30d9a647b1b8c
Reviewed-on: https://boringssl-review.googlesource.com/6040
Reviewed-by: Adam Langley <alangley@gmail.com>

Change-Id: I63c70f93a0f9395673c9fbe01eb5d864a14a48b6
Reviewed-on: https://boringssl-review.googlesource.com/5520
Reviewed-by: Adam Langley <agl@google.com>
Reviewed-by: Matt Braithwaite <mab@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>

(Based on Piotr Sikora's change:
https://boringssl-review.googlesource.com/#/c/1361)

Change-Id: I7b62b81f4e4ef3064eee1b39334dc2e50d17f163
Reviewed-on: https://boringssl-review.googlesource.com/1641
Reviewed-by: Adam Langley <agl@google.com>

BUG=396787

Change-Id: I72ddb0ec3c71dbc70054403163930cbbde4b6009
Reviewed-on: https://boringssl-review.googlesource.com/1581
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.)