Because time.Time doesn't work correctly with our YAML package, it is necessary
to introduce a type, util.Time, which serializes correctly to JSON and YAML.
Eventually we would like timestamping to cut across storage implementations;
for now, we set it in each storage.
Currently all registry implementations live in a single package,
which makes it bit harder to maintain. The different registry
implementations do not follow the same coding style and naming
conventions, which makes the code harder to read.
Breakup the registry package into smaller packages based on
the registry implementation. Refactor the registry packages
to follow a similar coding style and naming convention.
This patch does not introduce any changes in behavior.
