MAMA: Moved background thread destroy to stop (#326)
MAMA: Moved background thread destroy to stop (#326)

Was previously in mama_close when it should have been in mama_stop.

For details, see #319

Signed-off-by: Frank Quinn <8e90d92b6718ce33106d66386b493961926d3d82@gmail.com>
fquinner/OpenMAMA,fquinner/OpenMAMA,fquinner/OpenMAMA,fquinner/OpenMAMA,fquinner/OpenMAMA,fquinner/OpenMAMA,fquinner/OpenMAMA