The attached patch makes the data dir configurable and the user dir standard in linux.
It means that data can be specified as -DDATADIR="/usr/local/share/cubosphere" in the CFLAGS.
If -DLINUX is passed in the CFLAGS, cubosphere will use "$HOME/.cubosphere" as user dir.
These changes are necessary to enable packaging.
This patch is based on cubosphere alpha 0.03.