nested list with depth > 4

[tungcua66]

Do you want to request a feature or report a bug?

feature

What is the current behavior?

With current version, we cant have a nested list with a depth >4

What is the expected behavior?

Nested list with depth = 8, for example:

1. depth = 0
   1.1. depth = 1
   1.1.1. depth = 2
   1.1.1.1. depth = 3.
   etc...

Which versions of Draft.js, and which browser / OS are affected by this issue? Did this work in previous versions of Draft.js?

Version: 0.11.7, browser: chrome, firefox, IE, safari.