Added support for SWAP and WITH_EXCEPT_START

[ddouworld]

WITH_EXCEPT_START is simply put together with SETUP_WITH_A, but it works fine.
The test code for SWAP is as follows

def SWAP():
    my_array = [
        1,
        2,
        3,
        4,
        5,
        6,
        8]
    i = 1
    j = 3
    my_array[i], my_array[j], my_array[2] = my_array[j], my_array[i], my_array[4]

The generated code looks like this

def SWAP():
    my_array = [
        1,
        2,
        3,
        4,
        5,
        6,
        8]
    i = 1
    j = 3
    (my_array[i], my_array[j], my_array[2]) = (my_array[j], my_array[i], my_array[4])

It's not quite the same, but I don't think it should affect function much

[TiZCrocodile]

the problem with this:

my_array[i] = my_array[j]
my_array[j] = my_array[i]
my_array[2] = my_array[4]

is that the logic changes, for example

x=1
y=2
x,y = y,x

would replace them, but this

x=1
y=2
x = y
y = x

would result in both variables equals to y, because after x = y, now y = x, means y = y

[ddouworld]

Yes, you're right. I think I need to change it