Intersection circles : tools

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24608 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Intersection circles : improve algo code

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24609 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e