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>

TODO indicated that it was unused, and commented. Any existing users are already broken.

Change-Id: I75ebaf3f20015845d8c81eecffe2a4dfbdbe18e8
Reviewed-on: https://boringssl-review.googlesource.com/1386
Reviewed-by: Adam Langley <agl@google.com>

This change marks public symbols as dynamically exported. This means
that it becomes viable to build a shared library of libcrypto and libssl
with -fvisibility=hidden.

On Windows, one not only needs to mark functions for export in a
component, but also for import when using them from a different
component. Because of this we have to build with
|BORINGSSL_IMPLEMENTATION| defined when building the code. Other
components, when including our headers, won't have that defined and then
the |OPENSSL_EXPORT| tag becomes an import tag instead. See the #defines
in base.h

In the asm code, symbols are now hidden by default and those that need
to be exported are wrapped by a C function.

In order to support Chromium, a couple of libssl functions were moved to
ssl.h from ssl_locl.h: ssl_get_new_session and ssl_update_cache.

Change-Id: Ib4b76e2f1983ee066e7806c24721e8626d08a261
Reviewed-on: https://boringssl-review.googlesource.com/1350
Reviewed-by: Adam Langley <agl@google.com>

Previously, public headers lived next to the respective code and there
were symlinks from include/openssl to them.

This doesn't work on Windows.

This change moves the headers to live in include/openssl. In cases where
some symlinks pointed to the same header, I've added a file that just
includes the intended target. These cases are all for backwards-compat.

Change-Id: I6e285b74caf621c644b5168a4877db226b07fd92
Reviewed-on: https://boringssl-review.googlesource.com/1180
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.)