Commits on May 20, 2016

1. Ensure gzipped files have repeatable results …

   The gz format puts a timestamp in the compressed file. Therefore
   repeated runs produce different gz files even though the input data
   is the same. Use a timestamp of 0 to ensure the compressed data is
   the same when the input data is the same.
   
   Neither the gzip executable nor the libarchive library provide a way
   to specify the timestamp explicitly, so we set the modification time
   of the input file. This is going to be removed anyway, so it doesn't
   matter what it's set to.

   

   neilmayhew committed May 20, 2016
   7861941

2. Ensure repeatable html results by omitting timestamps

   

   neilmayhew committed May 20, 2016
   d147262

3. Ensure repeatable hints and icons results by not using parallelism …

   Parallelism gives rise to a non-deterministic ordering of the icons and
   hints. Removing parallelism makes no appreciable difference to the
   speed.

   

   neilmayhew committed May 20, 2016
   f529b96