Preparation for the ability to set horizontal spacing. Two types of horizontal positioning -- an offset from the default position (which doesn't affect the flow) and a padding (which does).
Also some package exports.

approximately the right place. It's also now calling a
DRAW-CURRENT-ELEMENT generic function so that it can be expanded for
notations and objects other than clusters.

Zoom functionality (and change of raster changing function names so that COM-ZOOM-IN means what it should)

New generic function SYSTEMS-PER-PAGE

Motivated by use as a webtoy:
* be careful in PCDATA not to take the node-value of something that's not
  a node;
* attributes in the wild aren't always the first element in the bar; search
  harder for them;
* new function PARSE-MXML-CLEF;
* new function GET-DTD-PATH.

The major thing that needs fixing is being currently unable to name and
refer to views with a sensible (unique) string name.

Key and time signatures now share a staffwise-elements slot in the stave.

thanks to Troels Henriksen fixing McCLIM.

tenuto and staccato articulation marks.

The quality of the graphical rendering of the marks is not really up to
scratch; horizontal placement seems to be off by somewhere between half
and one pixel, and of course a note with both marks on at once gets an
ugly graphical clash.  As I say, "work in progress".