Merge post-0.7.0 commits through 'c8250d8b8' into v0.7.2.

sdl_common.c has lost some commits in the restructuring and those
will need to be replayed over the restructured files for SDL1 and 2.

sc2/src/port.h

@@ -79,12 +79,24 @@
 
 
 #ifndef HAVE_STRUPR
+#if defined(__cplusplus)
+extern "C" {
+#endif
 char *strupr (char *str);
+#if defined(__cplusplus)
+}
+#endif
 #endif
 
 #if !defined (_MSC_VER) && !defined (HAVE_READDIR_R)
 #	include <dirent.h>
+#if defined(__cplusplus)
+extern "C" {
+#endif
 int readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result);
+#if defined(__cplusplus)
+}
+#endif
 #endif
 
 // Directories
@@ -161,10 +173,21 @@ typedef unsigned short mode_t;
 #ifdef _MSC_VER
 #	include <stdarg.h>
 // Defined in port.c
+#if defined(__cplusplus)
+extern "C" {
+#endif
 int snprintf(char *str, size_t size, const char *format, ...);
 int vsnprintf(char *str, size_t size, const char *format, va_list args);
+#if defined(__cplusplus)
+}
+#endif
+
 #endif  /* _MSC_VER */
 
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
 // setenv()
 #ifndef HAVE_SETENV
 int setenv (const char *name, const char *value, int overwrite);
@@ -178,6 +201,10 @@ typedef unsigned short wchar_t;
 typedef unsigned int wint_t;
 #endif
 
+#if defined(__cplusplus)
+}
+#endif
+
 #if defined (_MSC_VER) || defined(__MINGW32__)
 #	define USE_WINSOCK
 #endif