Pygame-menu

- Added ``PyInstaller`` support, 212, 264.
- Added ``pathlib.Path`` support on ``BaseImage`` and ``Image`` widget.
- Menu widget positioning fixes.
- Added ``SOUND_EXAMPLE`` to ``pygame_menu.sounds``.
- Fix ``ColorInput`` rendering.
- Improve docs and tests.

- Fixes 251, 252.
- Added v3 note.
- Improves docs.
- Added ``BaseImage`` methods ``get_path``, ``get_drawing_mode``, ``set_drawing_mode``, ``get_drawing_offset``, and ``set_drawing_offset``.
- New ``PYGAME_WINDOWCLOSE`` event locals.
- Fix several typing issues.
- Removed ``**kwargs`` from ``Menu`` constructor.
- Improve computation of max/min widget position.
- Improved widget positioning on Menu centering.
- New ``Menu`` method ``get_height`` and ``set_title``.
- New ``MenuBar`` widget method ``get_title_offset``.
- Fixed ``ScrollBar`` constructor parameter ``onchange``.
- New ``Widget`` methods ``get_position``, ``get_width``, ``get_height`` and ``get_size``.
- Fixed ``Selection`` ``get_height`` method.

- Fixed double widget background drawing, 246.
- New function ``is_event`` in ``pygame_menu.event`` module.
- New menu method ``set_onclose(onclose)`` and ``get_theme``.
- Added attributes to Menu.
- Now menu constructor copies the default theme.
- Set theme ``widget_background_inflate`` back to ``(0,0)``.
- Added widget ``selection_expand_background`` property and ``expand_background_inflate_to_selection_effect()`` method.
- Added ``set_backbox_border_width`` to ``MenuBar`` widget.
- Improve docs and tests.

- Docs fixes.
- Renamed ``BaseImage.apply_image_function`` ``func`` method to ``image_function``.
- Renamed widget method ``add_draw_callback`` ``func`` to ``draw_callback``.
- Renamed widget method ``add_update_callback`` ``func`` to ``update_callback``.

- Added widget transform methods ``rotate``, ``translate``, ``flip``, ``scale`` and ``rotate``.
- Fix ``BaseImage`` flip bug.
- Throw warning if Menu ``column_fit_text`` constructor parameter is enabled but ``column_max_width`` is None.
- Improve edge case while creating scrollarea if menubar height is greater than menu height.
- New menu methods ``get_menubar_widget()`` and ``get_scrollarea()``.
- New widget method ``get_surface``.

- Fixes widget padding if a background color is used, 242.
- New Menu parameter ``overflow``.
- Fix ``background_inflate`` docs.
- New Menu widget insertion parameter ``font_background_color``.
- New TextInput parameter ``input_underline_len``.
- New Menu method ``get_clock()``.
- New Theme ``widget_font_background_color`` property.
- New Selection method ``get_xy_margin()``.
- New Widget property ``lock_position``.
- New Widget methods ``has_attribute(key)``, ``remove_attribute(key)``, ``add_draw_callback(func)``, ``remove_draw_callback(callid)``, ``apply_draw_callbacks()``, ``add_update_callback(func)``, ``remove_update_callback(callid)``, ``apply_update_callbacks()``.
- Improve widget rendering.