db4o-sp Code-SVN

Created strategy for edge intersector - line arrangement. Implemented one concrete strategy of this type as Plane Sweep algorithm (Bentley and Ottmann with sweep line move from top to bottom). This algorithm is implemented to handle degeneracies as parallel edge with sweep line or more edges with one intersection point (all simply tested).
This is one from some part of implementation of topology graph (Create nodes and edges from geometry, Arrangement - this part, Noding - snap rounding, Labelling).