HQx rendering is rougher in devbuilds

[plums]

Here is a screenshot from 1.8.02, using HQ3x scaling and bilinear filtering:


Here is one from the current build with the same settings:


The edges of the pistol look much rougher in the second shot to me. This change is even more apparent when enemies and other sprites are up close (harder to get a direct comparison shot though).

I believe that gzdoom-G1.9pre-502-g0aba6e0.7z was the first devbuild where this change was noticeable, making https://github.com/coelckers/gzdoom/pull/6 the likely cause.

[plums]

To add to this: it appears that the HQx code at https://code.google.com/p/hqx/ actually produces different results than the original algorithm - much worse IMHO.