Invincibility frame

Invincibility frames are frames during which one cannot be hit.

These include:
 * When spawning. When one is on the platform after losing a stock and for 120 frames (2 seconds) after getting off it.
 * At the beginning of Get-up attacks and animations
 * At the beginning of Techs (all kinds)
 * When Rolling/Sidestepping/Dodging
 * At the beginning of wall jumps
 * At the beginning of certain moves, like Samus' and Bowser's Up + B's (Spin Attack and Whirling Fortress)