RTree optimization

[changliao1025]

In several places in the existing code, the following method is used:

index_vertex = RTree(max_cap=5, min_cap=2)
    for i in range(nVertex):
        lID = i
        x=aVertex_in[i].dLongitude_degree
        y=aVertex_in[i].dLatitude_degree
        left   = x - 1E-5
        right  = x + 1E-5
        bottom = y - 1E-5
        top    = y + 1E-5
        pBound = (left, bottom, right, top)
        index_vertex.insert(lID, pBound)  #
        pass

This may not be efficient since it can be replaced by the search_surrounding function:
https://github.com/Rhoana/tinyr/blob/master/tinyr/tinyr.pyx

[changliao1025]

The new method:

    #x=pVertex_in.dLongitude_degree
    #y=pVertex_in.dLatitude_degree
    #left =   x - 1E-5
    #right =  x + 1E-5
    #bottom = y - 1E-5
    #top =    y + 1E-5
    #pBound= (left, bottom, right, top)
    #aIntersect = list(index_vertex.search(pBound))
    aIntersect = list(index_vertex.search_surrounding([pVertex_in.dLongitude_degree, pVertex_in.dLatitude_degree]))