A few files reported by chekrefs are false positives. This patch adresses some of those. see P194
TODO: The GUI can now have includes in any subobject while it could only do so in page_*.xml files at the root level (Notice also that we now have two way to do includes)
Music defined by music.js are marked unused by the script, moving them to a JSON could be nice.
Alphamaps are hardcoded in C++, moving them to a JSON could be nice.