Added mutex and condition for thread initialization and revert recent priority initialization via pthread_attr_t.
Added mutex and condition for thread initialization and revert recent priority initialization via pthread_attr_t.

No more DIRECT_THREAD_WAIT_CREATE.
No more sched_yield().

deniskropp/DirectFB,deniskropp/DirectFB,kevleyski/DirectFB-1,mtsekm/test,djbclark/directfb-core-DirectFB,sklnet/DirectFB,lancebaiyouview/DirectFB,mtsekm/test,sklnet/DirectFB,DirectFB/directfb,kevleyski/directfb,sklnet/DirectFB,jcdubois/DirectFB,dfbdok/DirectFB1,jcdubois/DirectFB,lancebaiyouview/DirectFB,dfbdok/DirectFB1,kevleyski/DirectFB-1,kevleyski/directfb,deniskropp/DirectFB,mtsekm/test,kevleyski/DirectFB-1,DirectFB/directfb,kevleyski/DirectFB-1,lancebaiyouview/DirectFB,dfbdok/DirectFB1,DirectFB/directfb,kaostao/directfb,deniskropp/DirectFB,djbclark/directfb-core-DirectFB,Distrotech/DirectFB,kaostao/directfb,Distrotech/DirectFB,kevleyski/directfb,sklnet/DirectFB,kaostao/directfb,Distrotech/DirectFB,lancebaiyouview/DirectFB,djbclark/directfb-core-DirectFB,kevleyski/directfb,djbclark/directfb-core-DirectFB,jcdubois/DirectFB