3.9.0

• Update the biblio file to latest spec draft (this also has the effect of fixing clause xrefs to titles containing unprocessed ecmarkup).
• Exit with 1 when there are build failures.
• Spaces after !/? annotations in algorithms are now non-breaking.
• Added a new type of note - Editor's note! <emu-note type=editor>Note to the editors!</emu-note>.