Updated adapter to use composite and/or non-numeric primary keys if already defined in the database schema.
Refactored adapter for readability.
Refactored dumper to fix some issues with standard primary keys.  Update tests to include a standard primary key test.
Fixed schema dumper to pass active record specs.
Squashed commits
Merge branch 'primary-key-additions' of github.com:blackjk3/oracle-enhanced into primary-key-additions