free thread related memory created by pthread_create()

[Joël Krähemann]

Hi all

The very last entry of following shows the issue with pthread_create():

http://pastebin.com/aQfAQV2q

The threads are detached and leaks I believe this could be the cause
of performance problems with GSequencer.

http://www.nongnu.org/gsequencer/

Cheers,
Joël