Split the two command implementations into separate libraries (#2012)

This will allow us at the user code side to determine to include old commands, new commands or both.

wpilibNewCommands/src/main/native/include/frc2/command/ScheduleCommand.h

@@ -0,0 +1,46 @@
+/*----------------------------------------------------------------------------*/
+/* 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 <wpi/SmallVector.h>
+
+#include "CommandBase.h"
+#include "CommandHelper.h"
+#include "SetUtilities.h"
+
+namespace frc2 {
+/**
+ * Schedules the given commands when this command is initialized.  Useful for
+ * forking off from CommandGroups.  Note that if run from a CommandGroup, the
+ * group will not know about the status of the scheduled commands, and will
+ * treat this command as finishing instantly.
+ */
+class ScheduleCommand : public CommandHelper<CommandBase, ScheduleCommand> {
+ public:
+  /**
+   * Creates a new ScheduleCommand that schedules the given commands when
+   * initialized.
+   *
+   * @param toSchedule the commands to schedule
+   */
+  explicit ScheduleCommand(wpi::ArrayRef<Command*> toSchedule);
+
+  ScheduleCommand(ScheduleCommand&& other) = default;
+
+  ScheduleCommand(const ScheduleCommand& other) = default;
+
+  void Initialize() override;
+
+  bool IsFinished() override;
+
+  bool RunsWhenDisabled() const override;
+
+ private:
+  wpi::SmallVector<Command*, 4> m_toSchedule;
+};
+}  // namespace frc2