buildroot

qtuio: fix build issue because of missing include

TuioServer.cpp uses usleep but did not include <unistd.h>. This
patch adds the missing #include. This issue has been reported
upstream.

Signed-off-by: Stephan Hoffmann <sho@relinux.de>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>