Put some include-once and extern "C" blocks in the extras' headers.

(transplanted from 9ba19d71cc4a4dd5c5fafe0de37d09fff75e57f6)

extras/globbing.h

@@ -1,3 +1,6 @@
+#ifndef INCL_PHYSFSEXT_GLOBBING_H
+#define INCL_PHYSFSEXT_GLOBBING_H
+
 /** \file globbing.h */
 
 /**
@@ -30,6 +33,9 @@
  *  \author Ryan C. Gordon.
  */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /**
  * \fn char **PHYSFS_enumerateFilesWildcard(const char *dir, const char *wildcard, int caseSensitive)
@@ -73,5 +79,11 @@ __EXPORT__ char **PHYSFSEXT_enumerateFilesWildcard(const char *dir,
                                                    const char *wildcard,
                                                    int caseSensitive);
 
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* include-once blocker. */
+
 /* end of globbing.h ... */
 

extras/ignorecase.h

@@ -1,3 +1,6 @@
+#ifndef INCL_PHYSFSEXT_IGNORECASE_H
+#define INCL_PHYSFSEXT_IGNORECASE_H
+
 /** \file ignorecase.h */
 
 /**
@@ -44,6 +47,9 @@
  *  \author Ryan C. Gordon.
  */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /**
  * \fn int PHYSFSEXT_locateCorrectCase(char *buf)
@@ -71,5 +77,11 @@
  */
 int PHYSFSEXT_locateCorrectCase(char *buf);
 
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* include-once blocker. */
+
 /* end of ignorecase.h ... */