Add JSON as a valid storage format for databases.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Make help for table options refer to tables.

The help previously referred to databases, which was confusing.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Allow exporting all tables for non-CSV.

CSV output does not contain a table name, and therefore exporting all tables
would lose important information about which files were in which tables.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Pretty-print JSON output.

Sort the keys for YAML output, but don't pretty-print it, because it isn't
clear if that will affect its validity as YAML 1.0 and 1.1.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
List table name in JSON exports.

The code that cloned existing records in order to export them was not only
unnecessary, but also buggy.  Since it did not provide a table, this caused
JSON exports to have null in their place.  Remove this filter, since it has
not been needed since when Record objects had their table name stored in
their first field.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Merge branch 'master' into peter