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/cpp/commands/WaitCommand.cpp

@@ -0,0 +1,16 @@
+/*----------------------------------------------------------------------------*/
+/* 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "frc/commands/WaitCommand.h"
+
+using namespace frc;
+
+WaitCommand::WaitCommand(double timeout)
+    : TimedCommand("Wait(" + std::to_string(timeout) + ")", timeout) {}
+
+WaitCommand::WaitCommand(const wpi::Twine& name, double timeout)
+    : TimedCommand(name, timeout) {}