remove begin-rescue in favor of def-rescue
Use whitelist to pass valid connection parameters to PGConn.

All the valids parameters for libpq are used.

See http://www.postgresql.org/docs/9.1/static/libpq-connect.html for the
full list

Fixes #8784
Introduce ./bin for your app's executables: bin/bundle, bin/rails, bin/rake. Executable scripts are versioned code like the rest of your app. To generate a stub for a bundled gem: 'bundle binstubs unicorn' and 'git add bin/unicorn'
Merge pull request #8786 from jeremy/executables

Introduce ./bin for your app's executables: bin/bundle, bin/rails, bin/rake
Take the heat :fire:
Merge pull request #8788 from goshakkk/remove-begin-rescue

Remove begin-rescue in favor of def-rescue