Fixed service hook issues. More in details.

* Speedup in launching dependencies.
* Brought back performing cleanup of service indicators on afterStop.
* Disabled invoking validateSlot() in babySitter.
* Emitting validateSlot in restartSlot()

Signed-off-by: Daniel (dmilith) Dettlaff <dmilith@verknowsys.com>
Explanation about order of execution and dependencies of service hooks in README.

Signed-off-by: Daniel (dmilith) Dettlaff <dmilith@verknowsys.com>