[MODULES-690] - Fix server_package_name problem

Fix server_package_name been ignored and changed the default
installation to install the mongodb-org version when
manage_package_repo => true .
Fix lots of problems

- Add `mongodb_conn_validator` resource to block until the service is
  ready to accept connections. Goodbye sleeps! (May lead to increased
  puppet runtimes due to mongodb being so slow.)
- Make `Class['mongodb::client']` work on debian if a client package is
  available, such as when using the mongodb official upstream repo.
  Otherwise the class is a noop. This class used to just raise a warning
  on debian and do nothing ever, which meant you couldn't install the
  upstream mongodb client shell.
- Correct dbpath, config path, and client package name on debian.
- Update the tests and remove all the sleeps
Merge pull request #121 from hunner/renanvicente

(MODULES-690) - Rebase of #115 and fix other problems.