#2 Conversion size limit

[Peter S Galbraith]

The conversion size list should not exceed the size of
the images to process.

e.g. it prompts:

Conversion sizes [640x480 800x600 1024x768 1600x1200]

even in a directory in which the largest size is
1024x768; it would be best if it didn't list 1600x1200.

(Alternatively, copy the file without modification to
the 1600x1200 size (without enlarging it) and delete
them all if no files were ever reduced in size).

Peter