[sre] updating command management to avoid waiting thread

Update of the SREmain that was actively waiting the termination of all
running commands before do a system.exit. The active wait has been
removed as well as the system.exit.

sre/io.janusproject/io.janusproject.plugin/src/io/sarl/sre/boot/Boot.sarl

@@ -64,8 +64,7 @@ class Boot {
 	 */
 	@SuppressWarnings("discouraged_reference")
 	static def main(args : String*) : void {
-		val retCode = createMainObject.runSRE(args)
-		System::exit(retCode)
+		val retCode = createMainObject.runSRE(args)		
 	}
 
 }

sre/io.janusproject/io.janusproject.plugin/src/io/sarl/sre/boot/commands/AbstractRunCommand.sarl

@@ -166,16 +166,4 @@ abstract class AbstractRunCommand extends CommandWithMetadata {
 		bootstrap.startAgent(bootAgent, config.agentStartArgs)
 	}
 
-	/** Wait for the termination of the SRE execution.
-	 * This function returns when the SRE is stopped.
-	 * 
-	 * @param bootstrap the SRE bootstrap.
-	 */
-	@SuppressWarnings("discouraged_reference")
-	protected def waitForTermination(bootstrap : SREBootstrap) : void {
-		while (bootstrap.running) {
-			sleep(100)
-		}
-	}
-
 }

sre/io.janusproject/io.janusproject.plugin/src/io/sarl/sre/boot/commands/RunSingleAgentCommand.sarl

@@ -74,7 +74,6 @@ class RunSingleAgentCommand extends AbstractRunCommand {
 			}
 			var config = cli.synchronizeCliWithBootConfig(1)
 			bootstrap.startAgentsFromConfig(config)
-			bootstrap.waitForTermination
 		} catch (exception : Throwable) {
 			return CommandOutcome.failed(255,
 				MessageFormat::format(Messages::RunSingleAgentCommand_2, exception.localizedMessage), exception)

sre/io.janusproject/io.janusproject.plugin/src/io/sarl/sre/boot/commands/RunWithoutAgentCommand.sarl

@@ -73,8 +73,7 @@ class RunWithoutAgentCommand extends AbstractRunCommand {
 			val universeContext = sre.startWithoutAgent
 			if (universeContext === null) {
 				return CommandOutcome::failed(255, Messages::RunWithoutAgentCommand_3)
-			}
-			sre.waitForTermination			
+			}	
 		} catch (exception : Throwable) {
 			return CommandOutcome::failed(255, MessageFormat::format(Messages::RunWithoutAgentCommand_2, exception.localizedMessage), exception)
 		}