The <opensslfeatures.h> header provides #defines which are normally
declared by OpenSSL when features are disabled.
This way applications are able to detect which features were removed
from BoringSSL and use it as drop-in replacement for OpenSSL.
Inspired by LibreSSL, which provides similar header.
Change-Id: If4352743fd938267e2640fb09ca851464b9240b9
Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
Reviewed-on: https://boringssl-review.googlesource.com/1191
Reviewed-by: Adam Langley <agl@google.com>
