Probably best to keep the original format, trailing whitespace and all.

Change-Id: I81a0ac46fd4ab4bb9d2b03d930b191024971447c
Reviewed-on: https://boringssl-review.googlesource.com/2473
Reviewed-by: Adam Langley <agl@google.com>

Make the commands print a short usage summary and add a README file that
explains the dependencies.

Change-Id: I0c3f0713749ecfca23afaa2b536ac70dbdd7db0a
Reviewed-on: https://boringssl-review.googlesource.com/2471
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.)