Implemented:
 - added isset() checks to password encryption mode in remoting
 - if additional parameter "_ispconfig_pw_crypted" is set to "1" the password fields are not re-encrypted, this is useful when importing data from existing user-bases where no cleartext passwords are stored.
   Attention: crypted passwords need to have the same format or they won't work (i.e. CRYPT for CRYPT fields, PASSWORD() for mySQL fields)