<on-connect> to accept an arguments with the script name

this little patch makes the function source_run_script() to be compatible with getting an arguments after the script name, eg. /path/to/script.sh arg1

be aware that this is just a proof-of-concept, as i'm not a C developer but a PHP developer. i have tested it with Icecast-2.3.2 release, and it works just fine, BUT if you found a bug or some dis-functionality please rewire this patch to make it better.

just thought it would be nice to share.