Merge branch 'udmf-plane-linedefs' into udmf-scrollers

appveyor.yml

assets/CMakeLists.txt

assets/README.txt

extras/conf/SRB2-22.cfg

extras/conf/udb/Includes/SRB222_things.cfg

src/Makefile

src/Makefile.d/features.mk

src/am_map.c

src/am_map.h

src/apng.c

src/apng.h

src/asm_defs.inc

src/b_bot.c

src/b_bot.h

src/byteptr.h

src/command.c

src/command.h

src/config.h.in

src/console.c

src/console.h