Changes from 18/7/2014.

Changlog:

2014.07.18:
- Made the "RTSPServer" code more robust, to allow for the possibility of the same substream
  being "SETUP" by the same client more than once.  (This could cause a crash when streaming a
  MPEG Program Stream file, and potentially for other file types as well.)
  (Thanks to Yann Fleutot of "Stormshield" for reporting this.)
- Changed some error message output code that was allegedly causing compiler errors in Debian Linux.