#27 more flexible indentation of continued lists/tuples/dicts

[A. MacLeod]

I wanted to be able to indent a continued tuple more than one column when the beginning of the tuple is just sitting on the line by itself:

(long, sequence, of_items,
that, needs, to_be, wrapped) = input_list

^^^^ - I'd like to have it indent four spaces, rather than just one, but only in this case.. if it's not the first thing, I want normal behavior:

packed_entry = (long, sequence, of_items,
that, needs, to_be, wrapped)

^^
In these cases the continuation lines up with the open parenthesis (or bracket or brace in the case of lists and dicts, respectively).

Thus, this patch, which introduces the custom variable py-indent-continuations-further (boolean).

[A. MacLeod]

better continued tuple/list/dict indentation