Started a cleanup of smbpasswd related stuff. I've created a new file

Started a cleanup of smbpasswd related stuff.  I've created a new file
lib/smbpasswd.c which will contain routines related to manipulating
smbpasswd entries.

 - renamed and moved pdb_{get,set}hexpwd() functions
 - renamed and moved pdb_{decode,encode}acct_ctrl() functions
 - started hiding references to the cruftalicious
   NEW_PW_FORMAT_SPACE_PADDED_LEN constant
 - started gradual rename of references to acct_ctrl to acb_info which is
   the nomenclature used in MSDN and header files

There's still more work to be done.  Currently there are several places
where smbpasswd entries are iterated etc.  Ideally this should all happen
through the passdb system.
(This used to be commit 4a01e240305fb6fead973beef4937a016b15d744)