Added CButtonTranslator::IsAnalog(int actionID) for testing if an action may be analog
[joystick] Enable analog sticks to act in a digital fashion, imitating buttons.

For example, if an analog axis is set to LEFT (and limit is e.g. "-1") then moving left past 50% will send a LEFT action, delay, and then send a stream of left actions at some period until the axis is moved under 50%
Added Xbox 360 controller keymap for analog axis support