invenio-retest-demo-site: inactivate web tests

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
global: better hostname check

* Uses short hostname when doing hostname check.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
invenio-recreate-demo-site: localdomain treatment

* Does not retain `localdomain` as the domain name anymore,
  uses simple `localhost` in this case.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
global: CFG_INVENIO_DATABASE_PASS

* Introduces CFG_INVENIO_DATABASE_PASS to be able to set up DB user
  password.

* Assumes DB root password is an empty string.  Useful for fully
  automated unassisted installations.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>