Add expat 2.1.0 for Windows, Mac, and for local Linux builds (use system expat otherwise)

lib-src/expat/xmlwf/xmlmime.h

@@ -0,0 +1,19 @@
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Registered charset names are at most 40 characters long. */
+
+#define CHARSET_MAX 41
+
+/* Figure out the charset to use from the ContentType.
+   buf contains the body of the header field (the part after "Content-Type:").
+   charset gets the charset to use.  It must be at least CHARSET_MAX chars
+   long.  charset will be empty if the default charset should be used.
+*/
+
+void getXMLCharset(const char *buf, char *charset);
+
+#ifdef __cplusplus
+}
+#endif