a subtle, non-comprehensive change to address a recent Valgrind leak.  Using to establish base for bigger changes ... and get current test running again.
force .so modules of leveldb into memory for initialization early in eleveldb loading.
avoid badarg exception when closing db_refs being closed

DbObject::RetrieveDbObject() returns NULL for 2 cases: when the db_ref NIF
resource can't be retrieved, and when the "close requested" flag is already
set. But eleveldb_close() treats both NULL return cases as an error and
raises the badarg exception for both.

Modify DbObject::RetrieveDbObject() to add a defaulted third argument, a
pointer to bool that defaults to NULL. If non-NULL,
DbObject::RetrieveDbObject() sets the bool to true if the db_ref NIF
resource is successfully retrieved, false otherwise. This allows
eleveldb_close() to pass that bool argument and then use it to distinguish
between the two NULL return cases from DbObject::RetrieveDbObject().
Merge pull request #113 from basho/vinoski/close-badarg

avoid badarg exception when closing db_refs being closed
cleanup fact that LevelIteratorWrapper is shafing ItrObject's itr_ref but not pinning ItrObject in memory.
forgot to remove debugging line.
passing db pointer to MoveTask causing odd failure.  Remove while researching.
for safety, go ahead an populate MoveItem reference pointer to the DbObject.
cut/paste work ... non-functional
Code running.  eleveldb_close() executes too fast.  tests fail.  time for it to be async.
delete test files that got added
db and iterator close now reshaped to live in malloc memory instead of Erlang.  Currently a blocking close for both, will move to async after next round of tests.
db close is now async.  next up:  iterator close.
async iterator close.
make clearing of m_RecentErlangPtr the threading sync, not m_CloseRequested
address condition where m_RecentErlangPtr could be NULL during shutdown.
clear write segfault potential.  likely last implementation.
bring forward a change to RetrieveDbObject needed for tests
correct comment
merge conflicts resolved