Fixed infinite loop due to redirect with error on Default Page

Conflicts:
	errai-navigation/src/main/java/org/jboss/errai/ui/nav/client/local/DefaultNavigationErrorHandler.java
	errai-navigation/src/main/java/org/jboss/errai/ui/nav/client/local/Navigation.java
	errai-navigation/src/main/java/org/jboss/errai/ui/nav/client/local/api/PageNavigationErrorHandler.java
	errai-navigation/src/test/java/org/jboss/errai/ui/nav/client/local/res/TestNavigationErrorHandler.java
Minor refactoring changes for default page redirect loop fix

Conflicts:
	errai-navigation/src/main/java/org/jboss/errai/ui/nav/client/local/Navigation.java