[aescrypt] Another potentially widely useful UI feature.

How about a way to verify one's knowledge of a key without doing the actual bulk decryption. Suppose I have an .aes file and I would like to answer the question "Does this file have the password that I think it has?" without actually decrypting the file. Furthermore, there could be an optional checkbox on this UI to actually do bulk-decrypt the file to verify its integrity, but without creating an output file. These tools could be used, for instance, by Bob to confirm to Alice that a file (which is to be processed by Bob at some later date) was correctly received. Cheers ...