#244 file name in print header

[Peer Sommerlund]

When printing several files, it is not possible to see
which file a given page belongs to. There is also no
page numbers, (but this can be worked around by adding
line numbers)

I popose

• Add file name (and path?) to header (top inner/left)
• Add print date to header (top outer/right)
• Add page number to footer (bottom outer/right)