CCAR: improve the shutdown process

CCAR: improve the shutdown process
1- use salome_kernel.py module instead of salome.py in shutdownSalome.py to avoid calling Study
2- disconnect all connections in the connection manager
3- change the order of servers shutdown :
    - connection manager
    - study
    - module catalog
    - registry
    - launcher
    - logger
and add some waiting time between each shutdown because it is asynchronous.