SSR: Investigate possible off-by a pixel sampling / bleed

[gkjohnson]

See pixels on the ground that take on a bit of the sphere color:

It is helped (but not removed entirely) by remove binary search:

Possibly due to interpolated sampling?

[gkjohnson]

An off-by-one pixel issue is apparent in the translucent mesh demo.

Fixed by rounding the render target size