part4: adapt codebase to changes in lib/

mostly straightforward except for CVSFile / Filesystem. moved the former
into the newly created latter component. removed VFSUtil entirely (that
functionality is available from lib/file/file_system_util.h)

Xeromyces.cpp: simplify buffer handling since smart pointers are now in
play. also use WriteBuffer instead of membuffer.

This was SVN commit r5519.

source/graphics/UnitManager.cpp

@@ -10,7 +10,6 @@
 
 #include <float.h>
 
-#include "lib/res/res.h"
 #include "Model.h"
 #include "UnitManager.h"
 #include "Unit.h"