slice duck typed arrays and lists

runtimeservices.getslice can't handle simple slicing of arrays or lists (when there is no defaultmember attribute).

o as object //or duck if not in -ducky mode

o = [1, 2, 3]
print o[2]

o = (4, 5, 6)
print o[2]

The patch isn't pretty because of tortoisesvn, but one way to fix this is to add this to getslice:
if (target is IList && args.Length == 1 && args[0] is int)