Picking elements from a set

s = pick(V,k,Type)

Gives all possibilities of picking k elements from the set V with or without order and repetition.
V can be an array of any size and any type.
Type can have the following values: '', 'o', 'r', 'or'. 'o' means pick ordered list, 'r' means replace elements after picking.

s is an array with all picks, one per row.

Examples:

>> pick(0:1, 4, 'or')
ans =
0 0 0 0
0 0 0 1
0 0 1 0
0 0 1 1
0 1 0 0
0 1 0 1
0 1 1 0
0 1 1 1
1 0 0 0
1 0 0 1
...

>> pick('abcd', 2, '')
ans =
ab
ac
ad
bc
bd
cd

>> pick(1:3,3,'o')
ans =
1 2 3
1 3 2
2 1 3
2 3 1
3 1 2
3 2 1