Add option to save results to files

[CDrummond]

Add option (in config.ini?) to store analysis results within a file's tags. When analysing check for this tag an use results from there. Would need to decide on how to save - e.g. comma-separated list of doubles, json string, etc.

[audiomuze]

I've wanted to make the same suggestion for some time, but refrained. It'd make absolute sense to have the option to save the analysis results to the underlying file tags, obviating the need to ever have to analyse a given file again and making the analysis portable to any underlying application that wishes to use it.

I've gone down the road of writing a UUID tag to all my audio tracks because it enables me to maintain a tagging database independent of file location as well as backup metadata without having to also backup the underlying files. The UUID makes it simple to restore an older backup of my music and update the metadata to its most current version.

There's another upside here also that pertains specifically to FLAC files. Any standards compliant FLAC file has a MD5 stored in the STREAMINFO block. This presents an opportunity to crowdsource analyser metadata for users that choose to opt in - it'd need a tool to upload the md5 and associated analysis metadata to a hosted database, and the ability to query the database for analysis metadata, thus only needing to analyse files without a matching md5 in the hosted database.