Merge pull request #4 from Vash63/master

Added systemd service file. Tested on Archlinux.
Update README.rst
Update README.rst
Change name in ds4drv.service.
Use a JoystickLayout class instead of a method for each layout.

Makes is simpler to define new layouts.
Add xboxdrv and xpad-wireless joystick layouts.
Use correct vendor/product ids.
Add MANIFEST.in.
Release version 0.2.0.