Added cable subjects

[thedod]

• Added -s option for g2svg.py (see il-related.subjects for example subject file)
• svg.tmpl now shows subjects. also added 200x150px margin around graph (in hope it's enough for the text overlays).
• readable-svg.tmpl is my high-contrast color-blind version (if I use it for gh-pages, might as well be available at master)
• new il-related.reverb (extracted from more cables - see my latest gh-pages)

note that il-related.subjects was barbarically generated by grep of SUBJECT: in body_* (and then some vi trickery), but it should probably be generated at c2txt.py

[thedod]

Merged upstream subjects.list. Will regenerate gh-pages (current version doesn't deal with multiline subjects)

[wlwardiary]

looks like we worked on the same topic, it nicely fits together.

i added subjects.list and the extract of the subjects in ref.py yesterday. a simpel grep only gives you very partial and broken subjects. some combined regex magic solved the problem in 99.9% of the cases.

the subjects.list has the full subjects for all cables, so you can re-use it here.