:Add images/tp build

This adapts the same methodology I used for my SAPSF LP2017 talk to keep
third-party resources out of the repository.  This is not only good from a
licensing perspective, but also good for the repo and programatically
defines how I derive the image displayed on my site from a source image (and
proves that it does not constitute a derivative work, as it is not
transformative).

Makefile

@@ -78,16 +78,23 @@ thoughts:
 docs/papers/.list: thoughts articles
 	echo "$(articles) $(texticles)" | tr ' ' '\n' | tools/doclist >$@
 
+images: images/tp/Makefile
+	$(MAKE) -C '$(dir $<)' all check
+images/tp/Makefile: images/tp/gen-makefile
+	( cd images/tp/ && ./gen-makefile ) >$@
+
 pages: $(pages) $(pages_md)
 articles: $(articles) $(texticles)
 docs: pages articles
-www-root: docs thoughts
+www-root: docs thoughts images
 	mkdir -p www-root/papers
 	( cd docs/ \
 		&& find . -maxdepth 2 -name '*.html' -exec ../tools/doc-cp {} ../www-root/{} \; \
 		&& find . -maxdepth 3 \( -name '*.pdf' -o -name '*.dvi' \) -exec cp {} ../www-root/{} \; \
 	)
-	cp -rv images/ fonts/ www-root/
+	mkdir -p www-root/images/
+	cp -v images/*.* images/tp/*.png www-root/images/
+	cp -rv fonts/ www-root/
 	cp -rv _raw/* www-root/
 	cp -v style.css www-root/
 	mkdir -p www-root/docs

images/tp/.gitignore

@@ -0,0 +1,6 @@
+*
+!gen-makefile
+!remote-list
+!SHA256SUM
+!.gitignore
+

images/tp/SHA256SUM

@@ -0,0 +1 @@
+3a2fb99c4cbb929ee7a5c404f7b356fa9c5133145feaf834220cad4362d651d0  eff-42.png

images/tp/gen-makefile

@@ -0,0 +1,54 @@
+#!/bin/bash
+# Generate Makefile for third-party image download
+#
+#  Copyright (C) 2017 Mike Gerwitz
+#
+#  This program is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation, either version 3 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+##
+
+declare -r remote_file=remote-list
+
+cat <<EOF
+### GENERATED BY gen-makefile ###
+
+TORIFY="${TORIFY-torify}"
+
+images := $( cut -d' ' -f1 "$remote_file" | tr '\n' ' '  )
+
+.PHONY: all check clean
+
+all: \$(images)
+SHA256SUM: \$(images)
+	sha256sum \$(images) > \$@
+
+check:
+	sha256sum -c SHA256SUM
+
+clean:
+	\$(RM) \$(images)
+
+EOF
+
+while read out url convert; do
+  dest="$out"
+
+  echo "$dest":
+  printf "\t\$(TORIFY) wget -O %q %q\n" "$dest" "$url"
+
+  test -n "$convert" || continue
+
+  # faketime because of EXIF metadata
+  printf "\tfaketime 1970-01-01 mogrify %s %q\n" "$convert" "$dest"
+done < "$remote_file"
+

images/tp/remote-list

@@ -0,0 +1 @@
+eff-42.png https://web.archive.org/web/20170922020250/https://www.eff.org/files/2014/01/24/eff-logo-plain-rgb.png -trim -resize 42 -gravity center -extent 42x42