Oval tool filling pixels incorrectly for oblong shapes

[Cody811]

The oval shape is filling incorrect pixels along the X axis

X=2 Y=1

X=5, Y=1

X=6, Y=3

Y=3. X=6

[theabbie]

@Cody811 Might be an issue in algorithm, we will fix it, Thanks.

PixelCraft/lib/Shapes.js

Line 134 in cf69d93

function ellipse(rx, ry, pc){