Merge branch 'fixedpal' into 'master'

Fixing the reduced palette

Index number 254 remapped from a dark browny-orange to a dark blue. Otherwise unchanged; most of the assets we have currently created do not use the index for its previous purpose. It would be nice to get this merged quickly so that there is certainty about what we use going forward.

http://i.imgur.com/9xuQApq.png

root/toaster/fixedpal contains every necessary asset file, including the SLADE translation lump.

See merge request !77