ordered_remove: remove an index from a vector of cluster ID
In oslerinhealth/rewind: Reconstructing Etiology with Binary Decomposition

This function is called when removing a cluster.

1	ordered_remove(index, mylist, t)

`index`	an integer of cluster ID to be inserted
`mylist`	a vector of integer cluster IDs
`t`	the effective number of clusters

ordered_remove(3,c(1:3,5:10),7)
ordered_remove(3,c(1:10),7)


# some quick examples:

list0 <- c(1:7,0,0,0)
k <- 1
while (list0[k]==k){ k=k+ 1}; cm = k
while (list0[k]==k+1){ k =k+ 1}; ci = k+1
while (list0[k]==k+2) {k =k+ 1};  cj = k+2

a1 <- ordered_remove(3,list0,7)
a2 <- ordered_remove(5,a1,6)
a3 <- ordered_insert(cm,a2,5)

# end of examples.