Update ch03 to Grails 2.2.1.
Use version 1.2 of Resources plugin.
Remove references to 'homepage' from UserIntegrationSpec.

The `homepage` property is now on `Profile` rather than `User`, so it cannot
be used in the integration test unless a test `Profile` instance is created.
Sync ch04 with ch03.
Customise the dynamic scaffolding templates.

The scaffolding templates now use the read-only 'displayString' property on
domain instances when rendering links to associations. This also means I've
added the 'displayString' property to the existing domain classes.
Customise field order and error messages in scaffolding.
Add missing non-English message bundle to ch04.
Sync ch05 with ch04.
Remove dateCreated constraint from User domain class.
Add more sample data.
Add advanced search page.
Sync ch06 with ch05.
Complete PostController based on current ch. 6.
Remove tests that are no longer in ch. 6.
Fix up PostControllerSpec.
Remove custom validator from User.
Add styling for flash messages.
Add source code for chapter 7.