This is quite a major update (v1.50). The first post has most of the details. (THERE'S A NIFTY CONFIGURATION WINDOW!!
)
However, I thought I might just clarify the use of AutoKey. To use AutoKey, you need to select the contacts that you wish to encrypt with. From there, it will generate a key based on you and your selected contacts. This key will be the same for each one of your contacts who select the same people. The point of this was to make it more convenient for people so that they do not always have to exchange keys.
The problem with this is, as Cookie has said, the AutoKey's key is crackable. Therefore, the use of AutoKey should be used with care, but for more security, do not use AutoKey, but instead use a custom one.