[OPEN-ILS-DOCUMENTATION] PDF icon: licensing concern & fix

[Dan Scott]

Hey folks:

I noticed the Adobe PDF image on the bottom of the docs pages and thought
"Hmm..."; taking a quick look at
http://www.adobe.com/misc/linking.html#pdficon we're almost in
compliance, with a big "but":

"""
The Adobe PDF file icon is provided solely as an indicator of an active
link to a Portable Document Format file with a .pdf filename extension
created using an Adobe® Acrobat® product. 
"""

Emphasis on "created using an Adobe® Acrobat® product"; as ours is not,
we shouldn't be using that icon. (Actually, the icon isn't quite the
same; ours has "Adobe" on it, which is probably worse because then we're
contravening "3. You may not alter the Adobe PDF file icon in any
manner").

So, a quick peek at GNOME's icons shows the "Dropline Etiquette" set at
http://art.gnome.org/download/themes/icon/1049/ICON-DroplineEtiquette.tar.bz2
has an appropriately licensed (CC-BY-SA) icon called
/dlg-etiquette/scalable/mimetypes/gnome-mime-application-pdf.svg that
might meet our needs, if we don't want to create something ourselves.
I've pushed a branch called "new_pdf_icon" to the DIG repository that
contains a replacement GIF derived from the GNOME icon; to comply with
the BY-SA license, I have included a comment in the GIF that clearly
states the provenance of the icon.

In the spirit of "beg for forgiveness", I have gone ahead and pushed
this change to the master, rel_2_1, and rel_2_0 branches of the repo
too. This can obviously be changed later, but I thought it was important
to address this (relatively minor) licensing violation right away.

Dan