Added osgDB::stringcopy and stringcopyfixedsize

include/osgDB/FileNameUtils

@@ -18,6 +18,7 @@
 
 #include <string>
 #include <vector>
+#include <string.h>
 
 namespace osgDB {
 
@@ -131,6 +132,11 @@ struct FileNameComparator
     }
 };
 
+
+void stringcopy(char* dest, const char* src, size_t length);
+
+#define stringcopyfixedsize(DEST, SRC) stringcopy(DEST, SRC, sizeof(DEST));
+
 }
 
 #endif