Adds support for PGDATA changing in config_entry.pp
Ensure that data_directory is set in the config. per GitHub user tbd - PR#510 / PR#494 that was filed against wrong module branch"
Adds acceptance test for non default PGDATA, based on alternative_port_spec.rb
Fixes unit test for data directory
Merge pull request #514 from mixacha/pg_data_support

Adds support for PGDATA changing