Revert "nlecomposition: Start task and initialize the stack after chaining up...
Revert "nlecomposition: Start task and initialize the stack after chaining up to parent's change state function" This reverts commit 57d40bec. Apparently it causes timeouts in the unit tests on Jenkins and Thibault's machine, and in the gst-validate tests. Caused by elements staying in PAUSED and waiting to be set to PLAYING. Needs further investigation.