Movitz has new 'basic-vectors' data-structure, and improved GC.

I've just checked in the last pieces of the migration to a new
data-structure for vectors, called "basic-vectors". The most important
new feature is that the vector's length is now a fixnum, so that
vectors are now restricted to most-positive-fixnum (#x1fffffff) rather
than the old limit of #xffff.

One practical consequence of this, is that the example GC
implementation in los0-gc.lisp is now capable of supporting new-spaces
up to size 2 GB. However, I believe the practically useful range is
going to be below a few tens of MB. I've set the default size to 2 MB.

There have also been numerous bug-fixes. A new los0.img is being
uploaded to the clnet web-site.

-- 
Frode Vatvedt Fjeld