Add new C++ Command framework (#1785)

This is the C++ version of #1682.

The old command framework is still available, but will be deprecated.

Due to name conflicts, the new framework is in the frc2 namespace.
Eventually (after the old command framework is removed in a future year)
it will be moved into the main frc namespace.

wpilibcExamples/src/main/cpp/examples/HatchbotTraditional/include/RobotContainer.h

@@ -0,0 +1,54 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#pragma once
+
+#include <frc2/command/Command.h>
+
+#include <frc/XboxController.h>
+#include <frc/smartdashboard/SendableChooser.h>
+
+#include "Constants.h"
+#include "commands/ComplexAuto.h"
+#include "commands/DefaultDrive.h"
+#include "commands/DriveDistance.h"
+#include "subsystems/DriveSubsystem.h"
+#include "subsystems/HatchSubsystem.h"
+
+/**
+ * This class is where the bulk of the robot should be declared.  Since
+ * Command-based is a "declarative" paradigm, very little robot logic should
+ * actually be handled in the {@link Robot} periodic methods (other than the
+ * scheduler calls).  Instead, the structure of the robot (including subsystems,
+ * commands, and button mappings) should be declared here.
+ */
+class RobotContainer {
+ public:
+  RobotContainer();
+
+  frc2::Command* GetAutonomousCommand();
+
+ private:
+  // The robot's subsystems and commands are defined here...
+
+  // The robot's subsystems
+  DriveSubsystem m_drive;
+  HatchSubsystem m_hatch;
+
+  // The autonomous routines
+  DriveDistance m_simpleAuto{AutoConstants::kAutoDriveDistanceInches,
+                             AutoConstants::kAutoDriveSpeed, &m_drive};
+  ComplexAuto m_complexAuto{&m_drive, &m_hatch};
+
+  // The chooser for the autonomous routines
+  frc::SendableChooser<frc2::Command*> m_chooser;
+
+  // The driver's controller
+  frc::XboxController m_driverController{OIConstants::kDriverControllerPort};
+
+  void ConfigureButtonBindings();
+};