[karl1c]

I have added the ability to choose which file formats are synced in the plugin's settings.
This means ONLY those file formats specified will be synced.

I'm not sure how I feel about this as you can already choose which formats to sync by filtering the formats in Calibre itself (for example, formats:"=EPUB" or formats:"=PDF" will show only epubs and pdfs which you can then select all and run the plugin on). Let me know if you have strong views on this new feature.

Edit: as ilovejedd has pointed out, the above paragraph is wrong. Without the new feature, all formats would be synced even if filtering for particular format(s) in Calibre.

BTW, the filtering in Calibre allows you to sync specific authors, publishers, ratings, or whatever using the same technique.