A5 mostly did, but ran into trouble with longer comments on a tune.
This may give blank space after tunes where a long comment overflows
onto another page, but I think for now it's better to have each tune
at the top of the page.
Or rather, and this is the other change, in the middle of the page. Centre
the page content for A5 and Nook.
That way output where the colour isn't appropriate, such as Nook or the newly introduced
A4Lulu output (which is the A4 book but with white cover page and no end coloured page, and so
suitable for using as the content on Lulu, where the cover is separate) can omit the colour.
A lot of stuff was being duplicated between different page size. Consolidate where
possible, and in particular put as much into a single source file (dottes.tex) as
possible. Making a single Booke is now potentially quicker, as the tune pages
don't necessarily have to be regenerate every time.