skip compile when model file not contain entry point.

Message in console: "XXX is up to date. GWT compilation skipped"

my current project contain extra gwt model file to compile against firefox browser:

<module rename-to="login">
<inherits name="com.company.Login" />

<set-property name="user.agent" value="gecko1_8" />
</module>

It was working in 1.1 version, it looks like CompileMojo.java compilationRequired method should check the parent gwt model's entry point.