Alter escaping in postgresql::config::afterservice

This allows non-standard users (pe-postgres) to change passwords. Also
added a function to do escaping of the password, added system tests
and rspec tests for the function.
reverting path on exec
amending the unless on the exec for quoting also
modified tests
Add README entry for postgresql::plperl
Fix postgresql::plperl documentation
Merge pull request #229 from mcanevet/plperl

Add README entry for postgresql::plperl
Merge pull request #218 from fiddyspence/set_postgres_postgrespw

Alter escaping in postgresql::config::afterservice
Use boolean for refreshonly

Puppet::Type supports `:boolean => true` to create a
`resource.<property>?` method that is true or false based on the
`:true`, `:false`, `true`, or `false` value of the parameter.

This will allow accurate assesment of the refreshonly attribute for
testing.
Add specs for psql Type and Provider
Merge pull request #212 from hunner/handle_refreshonly

Handle refreshonly correctly