Snaps do not have a working home directory

[no-lex]

Due to the inability to cd into the execution directory, as a workaround, snaps must use the snap directory as their home directory for now. Because snaps are read only, nobody can actually save settings or screenshots if they are using the snap version of the game. The solution to this is to allow setting a media and home directory separately, rather than the hardcoded path currently used of .