VS2010 buildfixes.

The main issue was mostly that we have to build C files as C++ in some
cases, and extern "C" wasn't being used everywhere, so linker errors
popped up. The rest is the usual tedious VS2010 stuff like casting void*
to other stuff, so this commit as a whole is pretty boring!

desktop_version/src/CWrappers.cpp

@@ -1,11 +1,10 @@
+#include "CWrappers.h"
+
 #include <SDL.h>
 
 #include "Localization.h"
 #include "UtilityClass.h"
 
-extern "C"
-{
-
 char* HELP_number_words(int _t)
 {
     /* C wrapper for UtilityClass::number_words.
@@ -24,5 +23,3 @@ uint32_t LOC_toupper_ch(uint32_t ch)
 {
     return loc::toupper_ch(ch);
 }
-
-} /* extern "C" */