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.

wpilibOldCommands/src/main/native/include/frc/commands/WaitUntilCommand.h

@@ -0,0 +1,45 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2011-2019 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/Twine.h>
+
+#include "frc/commands/Command.h"
+
+namespace frc {
+
+class WaitUntilCommand : public Command {
+ public:
+  /**
+   * A WaitCommand will wait until a certain match time before finishing.
+   *
+   * This will wait until the game clock reaches some value, then continue to
+   * the next command.
+   *
+   * @see CommandGroup
+   */
+  explicit WaitUntilCommand(double time);
+
+  WaitUntilCommand(const wpi::Twine& name, double time);
+
+  virtual ~WaitUntilCommand() = default;
+
+  WaitUntilCommand(WaitUntilCommand&&) = default;
+  WaitUntilCommand& operator=(WaitUntilCommand&&) = default;
+
+ protected:
+  /**
+   * Check if we've reached the actual finish time.
+   */
+  virtual bool IsFinished();
+
+ private:
+  double m_time;
+};
+
+}  // namespace frc