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/test/native/cpp/frc2/command/CommandTestBase.cpp

@@ -0,0 +1,37 @@
+/*----------------------------------------------------------------------------*/
+/* 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "CommandTestBase.h"
+
+using namespace frc2;
+
+CommandTestBase::CommandTestBase() {
+  auto& scheduler = CommandScheduler::GetInstance();
+  scheduler.CancelAll();
+  scheduler.Enable();
+  scheduler.ClearButtons();
+}
+
+CommandScheduler CommandTestBase::GetScheduler() { return CommandScheduler(); }
+
+void CommandTestBase::SetUp() {
+  HALSIM_SetDriverStationEnabled(true);
+  while (!HALSIM_GetDriverStationEnabled()) {
+    std::this_thread::sleep_for(std::chrono::milliseconds(1));
+  }
+}
+
+void CommandTestBase::TearDown() {
+  CommandScheduler::GetInstance().ClearButtons();
+}
+
+void CommandTestBase::SetDSEnabled(bool enabled) {
+  HALSIM_SetDriverStationEnabled(enabled);
+  while (HALSIM_GetDriverStationEnabled() != static_cast<int>(enabled)) {
+    std::this_thread::sleep_for(std::chrono::milliseconds(1));
+  }
+}