dbfixer

Before commit 5be9b876691f0a11586490e408ab36fd1ec039fd, the database entries
which used uint64 keys used little-endian byte order. This caused the keys to
not sort of sequence order. Beginning in commit
5be9b876691f0a11586490e408ab36fd1ec039fd, the keys are now in big-endian byte
order.

This utility converts an old LE database into a new BE database. It should be
run exactly once when upgrading a server from commit
9073522ad45f36b756317d91f4682e58bb05ee52 to commit
5be9b876691f0a11586490e408ab36fd1ec039fd.