Functions for alternative password

  - create alternative password
  - delete alternative password
  - manage alternative password (create and delete work with this
    method)
  - using attribute user:def:altPassword:namespace

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NEED TO DO AFTER MERGING:
1] create new attributeDefinition user:def:altPassword:* (all
possible login namespaces)
2] set rights for this attribute
3] add these information to the changelog!!!
GUI: Do not check for similar users also for vo extension and group

- Disabled check also on auto-approve.
Merge pull request #442 from stavamichal/alternativePassword_fromSlava

Functions for alternative password
RPC: new methods for alternative password

- create alternative password
- delete alternative password
Merge pull request #448 from zlamalp/application

GUI: Do not check for similar users also for vo extension and group