[Gzz] Fillets and the new bouymanager

[Matti Katila]

Hello,

The next generation buoymanager doesn't fix the problem with fillets.
If you use e.g. SqFilletConnection it doesn't necessarily get stenciled 
and the part of the fillet is drawn outside of the buoy.

The problem exist because fillet is drawn after buoyRender():
    otherAnchorCS = otherNode.renderBuoy(self.vs, into, linkId, otherAnchor, 
None)
    # ...
    self.vs.map.put(lineconn, anchorUnit, self.vs.unitSqCS(otherAnchorCS, "UN"))

We need a way to draw the fillet inside renderBuoy call. Many kinds of 
fillets should be supported depending of the node type. For example 
ppcanvas to ppcanvas should be SqFilletConnection and ppcanvas to pagespan 
should made with LineConnector.

I think the default lineconnector must be used if no other is related but 
custom fillet should also be available.


   -Matti