Sensible filenames for downloadable pdf-userlists

[asokero]

After mass importing user lists to puavo users the downloadable PDF-file always has the same import.pdf-filename. When creating users for several schools and groups, this can be a bit frustrating as you have to manually rename the files. The downloadable pdf-file should be named with a sensible pattern like f.ex. year-school-group.pdf

[esamattis]

It's all cool in the new import tool!