adding configurable default values for the create form

This adds an optional hash to the route specification allowing
you to specify a default for each field.
Merge pull request #30 from msouth/feature/configurable_defaults

adding configurable default values for the create form
Rename default_field_values to values_from_database.

A little clearer this way I thik.
Wrapping.
Acknowledgement for msouth
Update Changes with msouth's contributions (thanks!)
Add acknowledgement for Rahul - sorry it's late!

Looks like I forgot to add an acknowledgement for Rahul Kotamaraju last time
round - sorry Rahul!
Updating Changes ready for release