webink v2.0

Split primary_key into primary_key and primary_key_type.
Split foreign_key into foreign_key and foreign_key_type.
!! This breaks existing projects as there is no array returned
anymore.

Added Database.query functionality to allow for custom return
structures (i.e. return as Array of Arrays instead of Array of Hashes).

Model.initialize allows for passing the params as Array additionally
to the existing Hashes.
Models without fields still only allow Hashes as there are no reference
values to map the Array against.