Fix for semicircle inversion, part of #2306

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@31830 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Fix for circle inversion in combination with point on path bug fixed (fix for #2306).

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@31831 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e