Comment # 47 on bug 60802 from Alexandre Demers

So I played with libtxc (removed it in fact) and tested some demos again. For
those that were not completely relying on libtxc, I observed the following:
- textures not related to libtxc were displayed correctly
- textures related to libtxc were not displayed AND were corresponding to the
corrupted textures seen when libtxc was available.