The basic idea here is that given non-profit-test-data.ledger herein,
there should be a script that I could run, in this fashion:
$ general-ledger-report -b 2011/03/01 -e 2012/03/01 -f tests/non-profit-test-data.ledger
that would generate:
non-profit-test-data_chart-of-accounts.txt
non-profit-test-data_general-ledger.ods
Note that the ODS file currently has placeholders, as I haven't fully
figured out how to use the =hyperlink() function to make relative
hyperlinks.