[Input] Legacy keyboard respects the KeyRepeat field.

If the legacy keyboard device receives a key down event with IsRepeat set it
will only raise it's own key down event if it's KeyRepeat field is set to true.

This is as documented, regression casused by refactoring. Fixes issue #102.

Also change the GameWindowState example to show setting of KeyRepeat to true
and false and how that changes the event counts for the legacy and new keyboard
devices.