More crash fixes in 1.0.02

There were several crash reports that I received by mail. They are addressed in 1.0.02. The program could crash or terminate with an assertion failure in these cases:

1. trying to repair broken ID3V2 tags that contain images


2. changing file names manually in the file renamer, if no pattern was defined


3. saving tag info for files that contain an ID3V2.4.0 tag (but only in some particular, rare circumstances)