Add some passing tests
Record basic working version
record working tests with sample data
clean up tests, emit no debug output

Fix up tests to run reliably.
According to the spec for update-pack, refs are supposed to be sorted, anyway.
clean up, add test for errors, add comments
Add more comments
Remove unnecessary test

After testing I determined only ENOTDIR is needed to detect keys.
remove log lines, bad comments
Fix bug causing one extra slash

Also clean up code a bit.  Tests pass.
remove un-needed call to slice
remove extra whitespace
Merge pull request #3 from bewest/bewest/fix-keys-recurse-directories

make `db.keys` recurse subdirectories to produce prefix based matches