logical hitting : lines

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@31915 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
logical hitting : use thickness for near/far z-values

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@31916 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e