add failing unit test that exercises the issue
remove debugging print, de-race the unit test.
it's possible, (via kill, and possibly other methods) to hang the
keydir in a frozen state forever, which basically stops all folding
and guarantees memory growth of at least 2x over time.  This change
factors out the cleanup and pending merge behaviors and adds another
point where it can be called, at handle GC time, which should have
better guarantees of happening.
- remove leftover exploratory code
- cleanup some whitespace
Merge branch 'develop' into bugfix/itercount-gc
Merge pull request #147 from basho/bugfix/itercount-gc

Fix potential keyfolders count leak
We've been seeing some nondeterministic test failures after the
multifold stuff went in, this patch is an attempt to make them stop
happening.

- bitcask_nifs: Prior to multifold, keydir_itr_many_update_test() and
  keydir_itr_many_out_of_date_test() tested different things.  They're
  also subject to a race condition that the test bots seem to hit all
  the time.  As of multifold, they become the same test, so rename,
  de-race, and deduplicate.

- bitcask: The fold_visits_frozen_test() and
  fold_visits_unfrozen_test() don't clean up their disk state between
  runs.  We've been seeing some timeouts, adding this cleanup to
  hopefully stop it from happening.
Merge pull request #151 from basho/multifold-test-stabilization

multifold test stabilization
Add failing tstamp stats test

This test demonstrates how putting on a key more than once in the same
file does not update the oldest/newest timestamp stats for that file.
When re-putting value, update tstamp stats

The old code was passing zero as the timestamp in the case of putting a
value for the same key in the same file. Fixed to use the entry's
timestamp.
add paranoid multifold test
Change test function name to avoid confusing EUnit
Set the hash symbol to dollars
Merge pull request #155 from basho/bug/er/schema-sub

Set the hash symbol to dollars
Merge branch 'lockstep-multifold-test' into develop
Merge branch 'develop' of github.com:basho/bitcask into develop
Fixed an issue with some multi_backend versions not matching regular
versions

Also added a test that will pick problems like that up going forward.
Whitespace fixes from PR #157
Merge pull request #157 from basho/bugfix/jd/merge-small-file-multi-schema

Fixed an issue with some multi_backend versions not matching regular versions
Restore fix to timestamp test

This was lost in the naughty force push that ate everybody. The original
commit is 324aab1c6efdb1c914e1bb7485bada2eac29c154.

This clears the time fudge and prevents code from using real timestamps
when fake ones were intended to verify the test.