format, remove redundant toString()
+ServiceActivator support to Shell load function;
+support for nsh-start ext config from sorcersoft.com distribution
Extract INetworkShell
change ShellCmd so it doesn't depend on DiscoCmd;
move ShellCmd to sorcer-api so it can be extended by 3rd party classes
Fix Activator to ignore directories and missing files
fix NetworkShell to support plugin commands