Bunch of notes deleted on crypt()

Earlier this year, with lots of help from Solar Designer and Pierre, I rewrote the crypt() documentation to clear up a lot of confusion. However, I failed to check over the existing user notes, and so am now deleting a bunch of notes that attempted to document what was missing in the main body, since we fixed most of these problems already. Just wanted to give you all a heads-up so you'd know why the flood of deletions came through on that entry.