Cleanup for publication

Removed figures from Relative Units. Too confusing.
Removed dead markup.
Fixed printing style.
Tidy.
Removed newtron from ack section, as he is an editor.
Tidy
small markup fixes
fixed duplicate id in markup
Trashed images we no longer need
Merge pull request #43 from ResponsiveImagesCG/pub_as_note

prepare for publication as Note