Added hurt animation, and further improved controls!

I added in a hurt animation that is composed of two parts: an initial part where the character is red, has no control, and goes flying in some direction; and a post-hurt part where the player has control but can't be harmed, and will rapidly switch between full opacity to half opacity. After that, the player returns to normal. I also managed to fix that weird bug where the sword could be aimed in a different direction than where the player is facing, plus I managed to make it so the player character will continue to grab directional events - even when in the middle of a swing - so that the user can take immediate control with a new direction as soon as the swing is over.