Update msdl to 1.2.4-r1.
While here, enable LICENSE.

Version 1.2.4-r1.
-msdl
- bugfix release
- fiexed bug about redirection (thanks for Mr.Jubany)
- fixed some codes

Version 1.2.4.
-msdl
- 10th release
- fiexed proxy string parse bug
- fixed is_url_valid_char(), added some missing valid characters
          (thanks for Mr.Jubany)
- fixed SETUP request routine, a=control can be both absolute/relative
          URL
- use stdout for error output. error message goes to stdout now!

(obache)