Buildbot:LXC

https://springrts.com/mantis/view.php?id=5294

sudo apt update
sudo apt install g++ make cmake p7zip-full ninja-build
sudo apt install libxmu-dev libxi-dev default-jre default-jdk \
         libcurl4-gnutls-dev libssl-dev libopenal-dev libvorbis-dev \
         libogg-dev libsdl2-dev libfreetype6-dev libfontconfig1-dev

# needed for building libILU.so in DevIL, which isn't really needed
sudo apt install freeglut3-dev

# required by spring, not actually used in DevIL
sudo apt install libgif-dev