recursively generates a Cantor distribution.
x = MakeCantor(x,n1,n2,p,a1,a2,b1,b2);
signal of size n, (initialized by x = zeros(1,n))
left border (initialized by 1)
right border (initialized by n)
first and second cutting position (for example 1/3 and 2/3)
weights to apply on [n1,a1] and [a2,n2]