Provide tools to allow user to set field dirty and not valid, providing

dynamic error message.

[#177]

To summarize:

1. Add name attribute to schema-form input fields. This allows us to query these fields by name, otherwise
    they're rather anonymous. For example, now we can do this in our controller:
    ```$scope.organizationEditForm[key].$dirty = true;```

    In the above example, ```key``` is a name attribute, and ```organizationEditForm``` represents a form. ```$dirty``` is used by schemaForm and Angular to indicate a form field with an error, so being able to set it is critical.
1. schemaForm now checks for the existence of model[key + '_error'], where key is the name of the field, as
    in 1, above. For example, if the field name is 'name', it checks for model['name_error']. If that exists, 
    schemaForm uses it's contents as the error message. This allows us to dynamically pass a field specific
    error message to schemaForm, all the way from the server side, which is a bit like the west side, 'cause it's
    just so far away.