This adds parameter documentation for Cluster.iMoveToJob (I think it
was not clear if the new or old node list is needed) and fixes other
docstring style issues.

After this patch, all modules except for CLI.hs (which has many
obvious declarations for command-line options) and QC.hs (unittests)
have 100% doc-strings.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

No code changes (except one definition being moved around in QC.hs)
are contained in this patch.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This just adds glue to allow replaying of tests using a given RNG state
and test size (both are needed for exact replayability).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Since current distros don't package anymore QuickCheck 1.x, let's move
to 2.x.

This requires also a few changes to the code:

- Test.QuickCheck.Batch doesn't exist anymore, so we need to write some
  scaffolding code to replace it
- the way test sizes are generated has changed, and we need to restrict
  (in some tests) the cluster size, as our code is not yet ready for
  hundreds of thousands of nodes in a cluster and we run out of stack
  (which could be a bug somewhere by itself, needs investigation)
- at least with GHC 7, floating point errors make a perfect cluster
  score even bigger, so we need to bump up the max. rounding error
  allowed

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>