Fix command line export
Created by: ederag
The first commit (905d83bd) was already prepared and used in export. The next two commits (8b166c47 and 45c5e870) did fix issue #373 (closed).
This removes the ReportWriter.export
function in reports.py
that was no longer used in hamster.
Since it lead to ValueError: I/O operation on closed file
anyway,
it was removed altogether.