java: Support for loading multiple mains

When using the MultiJarLoader as the main class, it will use a
configuration file for the java loading.  Each line in the file will be
used to start a main, you can use -jar in each line or specify a main
class.

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