Remove givenName and surname restrictions to registration data model

[typerandom]

Removes givenName and surname restrictions on the registration data model.

Important

This depends on the PR https://github.com/stormpath/stormpath-node-config/pull/61 before it can be merged.

How to verify

Verify that once the application is started the web.register.form.fields configuration (https://github.com/stormpath/express-stormpath/blob/master/lib/config.yml#L65) reflects the account schema of your default directory.

Fixes https://github.com/stormpath/stormpath-sdk-node/issues/526

[robertjd]

@typerandom FYI that I've rebased this one against master. This one will need a lot of work on the registration controller tests. I pushed one small fix that fixed some of the failing tests. I'm testing while linked to stormpath/stormpath-node-config#61