add support for array rvalue, extended to multi-dimensions list access on underlying python object.
Syntax, x = [1,2,3,[4,5]]; x[3,0] == 4, x[3,1] == 5, x[0] == 1
N.B. assignment, i.e. lvalues are not supported on arrays at this moment.
array r-value applies for dict
Merge remote-tracking branch 'upstream/master'