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/WaitUntilCommand.h

@@ -0,0 +1,52 @@
+/*----------------------------------------------------------------------------*/
+/* 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 "CommandBase.h"
+#include "frc/Timer.h"
+#include "frc2/command/CommandHelper.h"
+
+namespace frc2 {
+/**
+ * A command that does nothing but ends after a specified match time or
+ * condition.  Useful for CommandGroups.
+ */
+class WaitUntilCommand : public CommandHelper<CommandBase, WaitUntilCommand> {
+ public:
+  /**
+   * Creates a new WaitUntilCommand that ends after a given condition becomes
+   * true.
+   *
+   * @param condition the condition to determine when to end
+   */
+  explicit WaitUntilCommand(std::function<bool()> condition);
+
+  /**
+   * Creates a new WaitUntilCommand that ends after a given match time.
+   *
+   * <p>NOTE: The match timer used for this command is UNOFFICIAL.  Using this
+   * command does NOT guarantee that the time at which the action is performed
+   * will be judged to be legal by the referees.  When in doubt, add a safety
+   * factor or time the action manually.
+   *
+   * @param time the match time after which to end, in seconds
+   */
+  explicit WaitUntilCommand(double time);
+
+  WaitUntilCommand(WaitUntilCommand&& other) = default;
+
+  WaitUntilCommand(const WaitUntilCommand& other) = default;
+
+  bool IsFinished() override;
+
+  bool RunsWhenDisabled() const override;
+
+ private:
+  std::function<bool()> m_condition;
+};
+}  // namespace frc2