Bug 11401 - Decode the hashed PIN from NL before saving it in Koha

When a new user is imported from NL, the hashed PIN is now decoded
before it is saved as part of the user data. Before it is saved in
it is of course encrypted/hashed. This means that patrons can use
their NL PIN codes to log into Koha, after thir data have been
imported.

A secret key is used in the decryption, which is only available to
Norwegian ILS vendors. The key should be added to the
koha-conf.xml config file, thusly:

<yazgfs>
  ...
  <config>
    ...
    <nlkey>xyz</nlkey>
  </config>
</yazgfs>
Bug 11401 - Only show fields with values on NL search results
Split names from NL into firstname and surname
Add email address to Koha/NorwegianPatronDB.pm
Fix encoding problems and display of sync data on moremember.pl
Make it possible to turn syncing on and off again
Save the hashed PIN from NL in borrower_sync.hashed_pin on import
Send the value of borrower_sync.hashed_pin as PIN to NL when syncing from Koha to NL
Set borrowers.userid = cardnumber on import from NL
Keep borrower_sync.hashed_pin updated when users are edited
Update borrower_sync.hashed_pin when a new patron is added by hand
Remove some debug cruft
Add some checking for sync data before using it