renamed t_color to t_fill, which is more correct
rewrote fill tween for solid fill

the rgba values are now cached and string parsing happens just once
rewrote the fill tween for linear and radial gradients
fixed the accidental anmGuy path screw-up
Merge remote-tracking branch 'origin/master' into color-tween
implemented stroke and moved color stuff around
Merge pull request #189 from Animatron/color-tween

Color tween: T_FILL + T_COLOR