Remove all trailing spaces

No real changes, just clean up sources by removing trailing spaces from
all the non-generated files.

This should hopefully avoid future commits mixing significant changes
with insignificant whitespace ones.

src/common/memory.cpp

@@ -27,7 +27,7 @@
     #include "wx/app.h"
     #include "wx/hash.h"
     #include "wx/log.h"
-    #include "wx/wxcrtvararg.h" // for wxVsnprintf 
+    #include "wx/wxcrtvararg.h" // for wxVsnprintf
 #endif
 
 #if wxUSE_THREADS