Change-Id: I5175ba1b316e381949c820211769fbd636fe645e
Reviewed-on: https://boringssl-review.googlesource.com/3024
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.)