Move cryptpassword tool to the sandbox for now

From Sergiu on the list:

• it is supposed to update from a wiki with plaintext passwords to one
  with hashed passwords
• does that using a groovy script, an xwiki.jar and a hibernate config file
• it is currently not working out-of-the-box, as it uses a deprecated
  path to locate the xwiki jar
• it does not work with virtual wikis, just the main one
• it should be refactored into a proper tool, and it should be
  referenced in the upgrade notes for 1.0 => new releases (I think 1.0
  still had plaintext passwords, we should check when exactly did this change)
• after it is clean enough, it should be moved back into the trunks