Compound-doc changes committed

[Mike Kestner <mkestner speakeasy net>]

I just committed the previously proposed changes to restructure the
compound document architecture for bonobo-2.0.  Both libbonobo and
libbonoboui were tagged with BEFORE_DOC_REWRITE and AFTER_DOC_REWRITE
surrounding the commits. 

An initial stab at reimplementing the sample-container has begun in the
samples directory, but it still has some initialization issues and is
lacking a sample component to test with. I'll be porting bonobo-draw
shape objects to the CanvasComponentFactory interface shortly for
further example code.

Mike