Improve readme, document api
Improve logic for stream indexes
Improve api

Add options object for future extensibility. Maintain backwards
compatibility with old api.
Add option to use id3v2.3

For Windows Explorer compatibility. See #8
(https://github.com/parshap/node-ffmetadata/pull/8).
Add dry run option
Add test for id3v2.3 option
1.2.0