Merge branch 'master' into 'feat/protobuf-protocol'

# Conflicts:
#   server/src/timer.rs

gravity fix

extend module system in client

merge

gravity added, client still broken

resolve merge conflict

Merge branch 'master' of https://gitlab.com/starkingdoms.tk/starkingdoms.tk

other players added, we'll see if it works

fix spacetime builds in nested subdirectories

fix build script for client

rename st to spacetime