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