Add initial system test

Add some initial system tests.  This highlighted issues:
- That files deleted by compaction would be left orphaned and not close,
and would not in fact delete (now deleted by closure only)
- There was an issue on stratup that the first few keys in each journal
would not be re-loaded into the ledger

include/leveled.hrl

@@ -42,6 +42,7 @@
 -record(bookie_options,
                        {root_path :: string(),
                         cache_size :: integer(),
+                        max_journalsize :: integer(),
                         metadata_extractor :: function(),
                         indexspec_converter :: function()}).