Fix subpixel sizes support

[el-fuego]

When you are using of non-integer values for the sizes, offsetWidth can be differ per each element in a list

// What was used
$$('.item').map(i => i.offsetWidth)
(8) [199, 200, 199, 199, 199, 200, 199, 199]

// Computed css styles
$$('.item').map(i => i.style.width)
(8) ["199.5px", "199.5px", "199.5px", "199.5px", "199.5px", "199.5px", "199.5px", "199.5px"]

// BoundingClientRect
$$('.item').map(i => i.getBoundingClientRect().width)
(8) [199.5, 199.5, 199.5, 199.5, 199.5, 199.5, 199.5, 199.5]

Compatibility: https://developer.mozilla.org/en-US/docs/Web/API/Element/getBoundingClientRect

[marcj]

Do you know why the browser engine sometimes returns 199 and sometimes 200 in offsetWidth for a value of 199.5?

[el-fuego]

Probably, a bug or trying of use the same summ result as the container offsetWidth

[marcj]

Ok cool, thanks!