Keep retransmit window size architecture-independent.

Parameters like these should not change between 32-bit and 64-bit. 64 is also
the value recommended in RFC 6347, section 4.1.2.6. Document those fields while
I'm here.

Change-Id: I8481ee0765ff3d261a96a2e1a53b6ad6695b2d42
Reviewed-on: https://boringssl-review.googlesource.com/2222
Reviewed-by: Adam Langley <agl@google.com>
2 files changed