Start up shell and management web in parallel

Start up shell and management web in parallel to make boot faster.  Note
that we also switch to latest mgmt.git which decouples JRuby and CRaSH
startup.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>