1.10.3: various additions

What's Changed

• Added cWX, cWY, cWWidth, cWHeight constants (AttributeMask) (#82)
• Added FocusChangeEvent to data Event (#81)
• Added setWMNormalHints (#83)

New Contributors

• @scolej made their first contribution in #81
• @n1essa made their first contribution in #83

Full Changelog: 1.10.2...1.10.3