Update Forge and Profiles to configure component-scan for base package

[jamesfredley]

Issue description

annotate Application with @ComponentScan(value = 'com.mycompany.myapp.custom')

This removes the need to define the beans one by one for the base application package in grails-app/conf/spring/resources.groovy

[jdaugherty]

Why can't we just annotate Application with @ComponentScan(value = 'com.mycompany.myapp.custom')?

We already know the package as part of Application, why not by default add scanning as part of the Application AST transform?

[jamesfredley]

Updated description to annotate Application instead

[jdaugherty]

We may want to finish converting the core grails framework to @Configuration prior to doing this. Any bean loading could cause issues if we aren't consistently loading in the same way.