automap improvements

- keyed doors are drawn in their respective color
- to distinguish them from keyed doors, regular walls and walls with
  ceiling level change are drawn in a tad darker red and yellow colors,
  respectively
- add another teleporter type and draw them in green

with IDDT cheats active:

- secret areas are entirely drawn in purple
- keys are shown as crosses in their respective color
- triangle size represents actual thing size
- countable kills are shown in red and countable items in yellow
Merge branch 'master' of https://github.com/fabiangreffrath/crispy-doom

Conflicts:
	src/doom/am_map.c