spatial-trees

Hi,

I've uploaded a new version of spatial-trees to cclan, with two fixes:

* conditionalize (on #+slow :-) the code checking that all the
  coordinates are in the right order in MAKE-RECTANGLE

* make spatial-tree-viz a static-file, so that if a user installs
  spatial-trees systemwide and then someone else installs clim, you
  don't get write errors.

Cheers,

Christophe