Fixed const iterator issue and something with the string utils.

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/branches/uni@13619 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/utils/string_utils.cpp

@@ -709,6 +709,11 @@ namespace StringUtils
 		    printf("Invalid version string '%s'.\n", s.c_str());
 	    return version;
     }   // versionToInt
+
+    const char* boolstr(bool b)
+    {
+        return (b ? "true" : "false");
+    }
 } // namespace StringUtils