Updated PostgreSqlNode

- Allow configuration file templates
- Set log file location as attribute
- Better control of commands used in driver

**Note** Requires #1083 for _processOwner_ flag
Added shared memory and max connections config with sample postgresql.conf
Updated database entity tests

- Changed database entities to implement DatastoreCommon
- Converted tests from Groovy to Java
- Fixed usage of DATASTORE_URL attribute
- Changed localhost PostgreSql tests to use less shared memory
- General tidy up of tests
Tidying up database entities
Fix issue with missing PostgreSql initdb command
Restore PostgreSql 8.x directories in search list
Added PostgreSqlNode icon for catalog entry
Configure postgres from install dir
Tidy up MySqlNode and MariaDbNode
Add method to copy postgresql.log back to Brooklyn
Update RubyRep use of config keys and sensors
Be stricter about PostgreSql version
Updated live PostgreSql tests to deal with differnt OS versions
Wrong user for stop effector processOwner flag
Move DATASTORE_URL attribute retrieval to preStart() from init()