Initial new OOP checkin.

It still needs work, but here is an initial pass at redoing this stuff in matlab's newer OO syntax.

The first thing to notice is what's missing. I've tried to strip away everything but what I needed to get this new framework started, e.g., for now no SC toolbox.

There are several changes, major and minor, from the original framework. It probably would have helped to track all of these, but I didn't (possibly go back and catalogue?). Some noticeable changes:
  * The mobius class is now a subclass of conformalmap.
  * The circle class, formerly gencirc, now acts as gencirc, zline, and, well, circle.
  * An attempt is made to centralise plot style.
  * Instead of 'clippingbox' or 'boundingbox', we now have 'plotbox' and 'boundbox', which give a padded box for plotting, and a box which specifies the extents of an object in the plane.
  * There is the start of a developer's document in the doc directory.
  * There is the start of a unit testing framework.

I've tried to follow your slides as a guide to command line use, but even there I've made changes. Until I get more written, you can see a little of what I've intended by looking at the 'spec_mobius_grids.m' script file.