Added md5 copyright

mongoose.c

@@ -3773,6 +3773,23 @@ static FILE *open_auth_file(struct connection *conn, const char *path,
 }
 
 #if !defined(HAVE_MD5) && !defined(MONGOOSE_NO_AUTH)
+/*
+ * This code implements the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest.	This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ *
+ * To compute the message digest of a chunk of bytes, declare an
+ * MD5Context structure, pass it to MD5Init, call MD5Update as
+ * needed on buffers full of bytes, and then call MD5Final, which
+ * will fill a supplied 16-byte array with the digest.
+ */
+
 typedef struct MD5Context {
   uint32_t buf[4];
   uint32_t bits[2];