The end screens include the corpses of the old version of the
assault tripod boss from before raymoohawk's change, and VICTORY2
also showed the old E2M8 level that has since been replaced. So
replace these images with up-to-date versions instead.
Freedoom Phase 1 needs endgame screens for the ends of episodes
2, 3 and 4. Add some basic screens that are essentially just
screenshots from level 8 of each episode. Set END0-END6 to be the
dummy empty graphic so that the game doesn't crash after E3.
This (for the time being) fixes the most egregious problems in #32.