Major code reorganization

This commit only updates the XCode project for the changes.
A later commit each will update it for scons and MSVC.

A few actual changes are mixed in:
- Add a prefix header for a handful of common definitions
- Moved current_cursor into the Cursor class as a static member
- Removed the make_cursor_sword and make_cursor_watch functions
- Include tests in the All target
- Remove redundant -l flags for Common and Common-Party (since they're included in the Link phases anyway)

src/scenedit/scen.main.cpp

@@ -11,7 +11,7 @@
 #include "scen.actions.hpp"
 #include "scen.fileio.hpp"
 #include "scen.btnmg.hpp"
-#include "soundtool.hpp"
+#include "sounds.hpp"
 #include "scen.townout.hpp"
 #include "scen.core.hpp"
 #include "scen.keydlgs.hpp"
@@ -23,7 +23,7 @@
 #include "strdlog.hpp"
 #include "choicedlog.hpp"
 #include "scen.menus.hpp"
-#include "restypes.hpp"
+#include "res_image.hpp"
 
 /* Globals */
 bool  All_Done = false;