work around unset SAGE_ROOT in Debian Sage package In this shell script, '$1' refers to the Sage binary that is to be used. The script is needlessly complex to accommodate for old versions of Sage, and perhaps the author is unaware of Sage's new command-line arguments. . Debian's `sage --root` is an empty string, so Cantor fails to start it. This patch is more succinct by starting the Sage shell which sets all variables appropriately, then starting 'sage-ipython' as desired. This way, as opposed to having '#!/usr/bin/sage --sh' as the shebang, still permits usage of local Sage copies.
