Deprecate XboxController in favour of wpilib's
Deprecate XboxController in favour of wpilib's

This adds a deprecation note in the documentation, and also adds a
warning on instantiation of XboxController, so that it appears in tests.

Twinters007/robotpy-wpilib-utilities,Twinters007/robotpy-wpilib-utilities,robotpy/robotpy-wpilib-utilities,robotpy/robotpy-wpilib-utilities