implement object[Integer...]

[stevengj]

Maybe make object[i,j,...] in Julia sugar for get(object, (i,j,...)), equivalent to object[i,j,...] in Python, for the common case of integer indexing (e.g. #149).

I would prefer to just make object[...] equivalent to object[...] in Python regardless of the index type, but then I wouldn't have a good syntax for Python's object.attribute (until some future Nirvana when dot overloading arrives in Julia).

[stevengj]

Would also be good to accept Range objects, which should be converted in this context to Python slice objects, for slicing.