Add hanging indent to Python mode

With this change it still aligns to the opening paren/bracket/brace in general. But if you go to a new line immediately after the opening paren/bracket/brace, it indents a fixed amount. This makes it easy to type things like:

```
foo = {
    1: 2,
    2: 3,
}

def myReallyLongMethod(
    someReallyLongParam="defaultValue",
    anotherReallyLongParam)
```