When a user deletes a buddy list entry, ask if the chat or channel should be destroyed / left or the contact should be deleted. In many cases, deleting a buddy from the blist would have no effect, since the buddy would show up again on the next startup, which is most likely confusing to the user. Just destroying the chat or the channel is dangerous too, so ask for confirmation every time this happens to let the user choose what to do with that entry.
Use purple_input_request with the masked bit set, instead of needlessly creating a request with generic fields. Implement correct sign in dialogue only queries for first and last name.
