Pygame-menu

- Fixes back event, 72.

- Added title shadow, 69.
- Added method to get selected widget.
- Fixed menu back/open events, 71.
- New examples format, now the files can be called from the terminal.
- Fixed textinput event cursor selection, 70.

pygame-menu` has been completely rewritten this version.

Core changes
- All menu elements were converted to **Widgets**.
- Added TextInput widget.
- New *locals* definitions.
- New element position within menu.
- Improved rendering methods.
- Improved library documentation.
- Added support for both python 2.7+ and 3.4+.

Events
- Added mouse support.
- Renamed all events.

Fonts
- Added system fonts.
- Added 4 new open source fonts.

Sounds
- Sound support are added in v2.0.0, both Menu and Widgets implements different types of sounds.
- This version introduces 8 different sound types.

Tests
- Added tests to the library.
- Added Travis-CI.

This release close issues 47, 26, 25, 18, 16, 12, 8.

- Minor improvements.

- Fixed typos, 24.

- Changed license to [MIT](https://opensource.org/licenses/MIT/).
- Created [PyPI](https://pypi.org/project/pygame-menu/) distribution.