Problem

For SVG output I believe the only way to suppress metadata output is to manually set all relevant fields (Date, Creator, Format, Type, etc.) to None. There should be an easier way to do so, either by passingmetadata={} or by passingmetadata=None. Hopefully this can be made consistent with the other backends too...

Proposed Solution

Support eithermetadata={} ormetadata=None to mean "suppress all metadata".