Adapt puppetlabs-postgresql to Fuel

Fuel uses a custom package name "postgresql" instead
of "postgresql94", so this value needs to be passed,
along with bindir value.

Also adapted all manifest references to postgresql::db to
postgresql::server::db.

Change-Id: I1ec329ee31ecc6edfd357329bfc84df95ecf7ddc
Closes-Bug: #1386118
Merge "Adapt puppetlabs-postgresql to Fuel"