APPROXIMATENEWPOINTS_SeparateInteriorBoundary
enforce separation of boundary and interior neighbors for initial approximation
for approximation of functin values of new / just-added points,
MESHFREE does an approximation out of the existing neighborhood.
The current parameter controls, what neighbors are tobe used.
value = 0 -> no separation. new interior or boundary point: use all neighbors for approximation
value = 1 -> separation switched on : new boundary points: use only existing boundary neighbors
-> new interior points : use ALL existing nbeighbors
value >= 2 -> separation switched on : new boundary points: use only existing boundary neighbors
-> new interior points : use interior nbeighbors, boundary points are used with a small weight of 10^(-(value-1))
default :: 1