only notify when the lobby settings differ from the default
announce map changes
announce kicks and bans
make the change notifications more natural
notify about difficulty level changes
disable music installation during a game

closes #6058
don't display idle overlays during actor transformations

fixes #6018
ITeleportable does not exist anymore
self-document CrushClass of crates
let supply trucks spawn money crates upon destruction
ContainsCrate is redundant to LeavesHusk
Sonic Tank offset
Remove TakeOff activity from ReturnToBase
Merge pull request #6160 from cjshmyr/returntobase

Remove TakeOff activity from ReturnToBase
Merge pull request #6155 from Phoib/sonicbeam

Sonic Tank offset
use ToLowerInvariant for all weapon rules
Merge pull request #6163 from Mailaender/shrapnel-lowercase-weapon

Fixed ThrowsShrapnel not using lower case weapon names.
Merge pull request #6152 from Mailaender/money-crate

Added money crates to be spawned by destroyed supply trucks
Write trait requirements in documentation.
IonCannonPower can now define how many ticks into animation the weapon impact happens (as opposed to at the end of the animation).