Move addpubkey from the utils to account directory. Note that I copied
the RCS control file in the repository so the history is left intact. Two new modes, which used to be in the old mkacct. There is an init mode, which is used on new users to create the initial pub key. There is also a write mode, which is used regenerate the authkeys files for people after they add/delete keys via the web interface. Used to be that addpubkey wold add the key to the DB, but mkacct would deal with creating the authkeys files. All this functionality is now localized in this one script.