Improve permissions and ownership for output files

[josteinaj]

The output files are currently owned by root. For instance, an output report HTML document will end up like this:

244K -rw-r--r-- 1 root    root    243K sep.   8 09:04 report.html

It should be possible to set the owner and group of the output files, for instance as environment variables. And the permissions should probably be something like 664, so that other users can access the files.