message: Remove `using namespace NAS2D;` from `Button`
diff: #include <NAS2D/Math/MathUtils.h>
  -using namespace NAS2D;
  -
  -
  Button::Button(std::string newText) :
  mButtonSkin{
  {
  @@ -51,7 +48,7 @@ Button::Button(std::string newText) :
  {
  text(newText);
  - auto& eventHandler = Utility<EventHandler>::get();
  + auto& eventHandler = NAS2D::Utility<NAS2D::EventHandler>::get();
  eventHandler.mouseButtonDown().connect({this, &Button::onMouseDown});
  eventHandler.mouseButtonUp().connect({this, &Button::onMouseUp});
  eventHandler.mouseMotion().connect({this, &Button::onMouseMove});
  @@ -75,7 +72,7 @@ Button::Button(const ButtonSkin& buttonSkin, ClickSignal::DelegateType clickHand
  Button::~Button()
  {
  - auto& eventHandler = Utility<EventHandler>::get();
  + auto& eventHandler = NAS2D::Utility<NAS2D::EventHandler>::get();
  eventHandler.mouseButtonDown().disconnect({this, &Button::onMouseDown});
  eventHandler.mouseButtonUp().disconnect({this, &Button::onMouseUp});
  eventHandler.mouseMotion().disconnect({this, &Button::onMouseMove});
  @@ -118,11 +115,11 @@ bool Button::hasImage() const
  }
  -void Button::onMouseDown(EventHandler::MouseButton button, NAS2D::Point<int> position)
  +void Button::onMouseDown(NAS2D::EventHandler::MouseButton button, NAS2D::Point<int> position)
  {
  if (!enabled() || !visible()) { return; }
  - if (button == EventHandler::MouseButton::Left)
  + if (button == NAS2D::EventHandler::MouseButton::Left)
  {
  if (mRect.contains(position))
  {
  @@ -140,11 +137,11 @@ void Button::onMouseDown(EventHandler::MouseButton button, NAS2D::Point<int> pos
  }
  -void Button::onMouseUp(EventHandler::MouseButton button, NAS2D::Point<int> position)
  +void Button::onMouseUp(NAS2D::EventHandler::MouseButton button, NAS2D::Point<int> position)
  {
  if (!enabled() || !visible()) { return; }
  - if (button == EventHandler::MouseButton::Left)
  + if (button == NAS2D::EventHandler::MouseButton::Left)
  {
  if (mType == Type::Push)
  {
  @@ -178,7 +175,7 @@ void Button::draw() const
  {
  if (!visible()) { return; }
  - auto& renderer = Utility<Renderer>::get();
  + auto& renderer = NAS2D::Utility<NAS2D::Renderer>::get();
  const auto& skin = (mIsPressed) ? mButtonSkin.pressed :
  (enabled() && mMouseHover) ? mButtonSkin.hover : mButtonSkin.normal;
  