core: changes to scheduler module

1. Moved all the scheduler code to utils
2. Changed The shceudler to be a non EJB singletone
(in the future this will be CDI bean)

Change-Id: Iaf02ee983d0d27ea580c0d0d3ae05e466d8c7051
Signed-off-by: Yair Zaslavsky <yzaslavs@redhat.com>