pe: be less chatty

ignore by default audio, images and videos attachments we can relax the rule as we go.

mexp: defer skip test after $tid is set otherwise we run with an undef $tid when processing new replies to existing threads.

mkindex: adjust pledge for cross-filesystem move()

use move from File::Copy instead of rename i was reminded that rename doesn't work across filesystems. `move' from File::Copy attempts to use rename and falls back to a copy+unlink, which is the thing we need.

pledge and unveil the scripts

drop needless mkdirs

css: simplify rule for threads vertical lines netsurf' css engine didn't handle the "> ul ul" selector correctly. rephrase it so even netsurf is happy :)

mexp: handle the body line by line

move the mid -> path code to a sub in the package

drop needless chomp

move some common code in a module

don't export the mbox this wasn't a good idea as the mbox contains sensitive data (IP addresses, hostnames and whatnot). Not good to publish on the web. Reminded by Stefan

some tweaks to the generated HTML

simplify the makefile move the logic of the export to gotmarc, where it's easier to set up the correct env. While here improve the makefile to generate the images and the copy the style only if needed.