fixes for coil design
fixes for magnet-design

* Allan's graph re-drawn
* Figure for coupling oscillations
intro tidied up
magnet theory tidied up
add magnetisation equations for planar multipole arrays
qzs tidied up
xpmt (mostly) tidied up
changes to maths notations should have been committed earlier, I suspect
WHOA SECOND DRAFT
rewrite abstract
start nomenclature
working on the nomenclature

lots of details to sort out!