Fix album art bug

Previously, script would hang on a Bandcamp without album art, as here:  http://yesmaam.bandcamp.com/album/stirrin-da-mudd

Fix properly handles such a case by displaying a message after encoding.
Fix typos

Just a couple small typos
Fix typos
Fix typos
Merge pull request #12 from mtchllbrrn/master

Fix album art bug, typos