Implement list pop method

[deeesp]

Attribute errors occured using list. ​

Python (expected)

>>> a.pop()
4
>>>a
[1,2,3]
>>>a.pop(1)
2
>>>a
[1,3]

gpython (Actual)

>>> a = [1,2,3,4]
>>> a.pop()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
    FIXME line of source goes here
AttributeError: "'list' has no attribute 'pop'"

[xarus01]

I'll work on this issue.

[ncw]

I'll work on this issue.

Thank you :-)