update #12 - v1.15.6 available... (small bunch'o'pre-xmas-somethings)

v1156 [GEN] netcode: ignoring 224.x.x.x multicast data (leading to never-ending error messages and thus performance loss) v1156 [GEN] map navigation: mapping for cursor keys added. v1156 [MAP] swamps - toxic areas are now better recognizable. v1156 [MAP] paradise found - toxic areas are now better recognizable.

Cheers & a merry, merry x-mas, Roman