Ambiguous symbols - simple solution

[mateusz@…]

This is a very simple solution for ambiguous symbols introduced in report:
#57 - Class naming changes proposal

As we talked today with strk, the #57 requires wider discussion,
so for now I suggest to use simple solution - qualified name like:
using namespace geos;
//...
geom::Polygon

Example of error send by VC++ 8.0:
error C2872: 'Polygon' : ambiguous symbol	geossourceoperationpredicateRectangleIntersects.cpp 131

Simple fix is in the patch attached to this report.