stdext: fix string.split(str, "") infinite loop

pg2: add unloading signal

random: add shuffle

random: use full integer range when lua 5.4 is available

hook-sys: also print function source on errors

getargs: show better 'bad args' error for tables, strings

stdext: add string.quote

exchange: set _type=table in resource list schema

debug: don't crash trying to integer-index a userdata

cargo: allow items to specify their cargo drop colors

cargo-menu: show a 'price' field if the item defines one

action-comms: allow explicit empty-string comms message to mean 'no response'

action-main: fix broken order handling

action-main: fix spread-update causing button breakage

schema: add _metatable check