Renaming the module package should also update .gwt.xml and other files

[ksfreitas]

I created a new GWT project in NB 6.0 (Win XP, JDK 1.6). After the initial
project creation I realized I wanted to refactor/rename the main package name,
so I used NB's Refactor->Rename functionality.

After it was completed, the Main.gwt.xml, welcomeGWT.html and gwt.properties
files still referred to the old package name.

The refactoring should have updated these two files as well to reflect the new
package name.

Imported from: http://java.net/jira/browse/GWT4NB-33