engine: initialize scheduling manager from InitBackendServicesOnStartupBean

Schedling manager initialize made public, call removed from constructor
and added to InitBackendServicesOnStartupBean. Additional logging for
better tracing.

Change-Id: Ic74d28c2aa9700527f6217f4de2a2b4527286317
Signed-off-by: Laszlo Hornyak <lhornyak@redhat.com>