NPE when AA injects into a non-generated class

[WonderCsabo]

Steps to reproduce:

1. Create an Activity, annotate with @EActivity
2. Create MyPref interface, annotate with @SharedPref
3. Inject MyPref_ mypref field into the Activity with @Pref
4. Make sure not the generated class is in the manifest.

After that, AA will crash with NPE in the PrefHandler. This is because we do not generate the class, instead we print an error about wrong component name in the manifest. But the PrefHandler still runs, and thinks the generated class holder exists...

Stacktrace:

java.lang.NullPointerException
    at org.androidannotations.handler.PrefHandler.process(PrefHandler.java:75)
    at org.androidannotations.handler.PrefHandler.process(PrefHandler.java:36)
    at org.androidannotations.process.ModelProcessor.processThrowing(ModelProcessor.java:145)
    at org.androidannotations.process.ModelProcessor.process(ModelProcessor.java:129)
    at org.androidannotations.AndroidAnnotationProcessor.processAnnotations(AndroidAnnotationProcessor.java:242)
    at org.androidannotations.AndroidAnnotationProcessor.processThrowing(AndroidAnnotationProcessor.java:184)
    at org.androidannotations.AndroidAnnotationProcessor.process(AndroidAnnotationProcessor.java:112)

Example project demonstrating the issue. The issue can be reproduced both from command line and Eclipse.