Added new topology layer to track sender a group is listening to.
Added unit test for new topology layer.
Added unit test for zoning in standard house.
Updated projects to point to correct build directory.
Updated project file to see if it fixes mac test error.
HACK to get tests running on Mac - xbuild for some reason does not copy ICSharpCode.SharpZipLib.dll for projects dependant on ohTopology, so I just reference the library directly :(
Merge branch 'master' of ssh://core.linn.co.uk/home/git/ohTopology

Conflicts:
	src/TestTopologym/TestTopologym.csproj