fix bug in numSegments ini;
Array<T,2> can not acces index[2].
SegmentSet<T> constructCircle -->> SegmentSet<T>* constructCircle
new function SegmentSet::writeSVG(std::string fname).
fix bug in size of edgeList
fix bug reported by "http://www.palabos.org/forum/read.php?11,6646"
fix bug reported by "http://www.palabos.org/forum/read.php?11,6848"