leap_cli should provide pre-hashed couchdb admin password and salt

We need this for two reasons:

• bigcouch is a fork of couchdb 1.1, and that version can't hash plaintext passwords in the config files on first start (this feature comes with 1.2)
• right now, puppet changes admin.ini on every run

see http://guide.couchdb.org/draft/security.html for details.

i.e.:

couch: 
  users: 
    admin: 
      password: c2a1e539827762dea5249331a9cbb769573121ec
      salt: 5250cf5642e37f5dd7ae30da3d52ed8f
      username: admin

(from redmine: created on 2013-03-10, closed on 2013-04-02, relates #1941 (closed))