[giac] fix for ticket 3430. radius now accept a circle equation, line accept a parallel line as 2nd arg. Fix for bisector with 3 points aligned.

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26405 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e