ipauser: User module extension

The ipauser module now supports all user settings and additionally to ensure
the presence of several users with the new users setting. The users setting
can also be used with other states, but it has to be limited to only contain
the name of the users.

There updated user management module is placed in the plugins folder:

  plugins/modules/ipauser.py

The user module now additionally allows to handle these user settings:

  initials
  principalexpiration
  random
  city
  userstate
  postalcode
  mobile
  pager
  fax
  orgunit
  manager
  carlicense
  sshpubkey
  userauthtype
  userclass
  radius
  radiususer
  departmentnumber
  employeenumber
  employeetype
  preferredlanguage
  certificate
  certmapdata
  noprivate
  nomembers

Here is the updated documentation for the module:

  README-user.md

New example playbooks have been added:

  playbooks/user/user_certificate_absent.yml
  playbooks/user/user_certificate_present.yml
  playbooks/user/user_present.yml
  playbooks/user/users_absent.yml
  playbooks/user/users_certificate_absent.yml
  playbooks/user/users_certificate_present.yml
  playbooks/user/users_present.yml
  plugins/modules/ipauser.py

New tests added for ipauser:

  tests/user/certificate/cert1.der
  tests/user/certificate/cert1.pem
  tests/user/certificate/cert2.der
  tests/user/certificate/cert2.pem
  tests/user/certificate/cert3.der
  tests/user/certificate/cert3.pem
  tests/user/certificate/private1.key
  tests/user/certificate/private2.key
  tests/user/certificate/private3.key
  tests/user/certificate/test_user_certificate.yml
  tests/user/certificate/test_users_certificate.yml
  tests/user/certmapdata/test_user_certmapdata.yml
  tests/user/certmapdata/test_user_certmapdata_issuer_subject.yml
  tests/user/certmapdata/test_users_certmapdata.yml
  tests/user/test_user.yml
  tests/user/test_users.yml
  tests/user/test_users_absent.yml
  tests/user/test_users_invalid_cert.yml
  tests/user/test_users_present.yml
  tests/user/test_users_present_slice.yml
  tests/user/users_absent.json
  tests/user/users_absent.sh
  tests/user/users_present.json
  tests/user/users_present.sh