Optimize "foo in 1..10" expressions

[antonmedv]

Automatically convert ast for foo in 1..10 from:

binaryNode{operator: "in", 
    left:  nameNode{name: "foo"}, 
    right: binaryNode{operator: "..", 
        left:  numberNode{value: 1}, 
        right: numberNode{value: 10}}}

To:

binaryNode{operator: "and", 
    left: binaryNode{operator: ">=", 
        left:  nameNode{name: "foo"}, 
        right: numberNode{value: 1}}, 
    right: binaryNode{operator: "<=", 
        left:  nameNode{name: "foo"}, 
        right: numberNode{value: 10}}}

[antonmedv]

Done in f7bcbfa