Refactor xinetd and xinetd::service

  - refactor xinetd class to be parameterized
  - rename $real_wait to $_wait to indicate it was munged
  - use validate_re function to verify tcp|udp
  - rename $xinetd_* to *
  - remove duplicate include xinetd
  - refactor template not to use scope.lookupvar
  - fix failing spec tests
  - add dependency on stdlib