Preserve list order according to parent start attribute

[manuelpuyol]

Right now, quoting bullet lists with ordering will change all indicators to 1. instead of keeping the actual order.

E.g, when you quote a list defined as:

1. Top level list one
    - 1. sublist one
    - 2. sublist  two
    - 3. sublist  three
1. Top level list two
1. Top level list three

it will generate:

> 1. Top level list one
>    
>    * 1. sublist one
>    * 1. sublist  two
>    * 1. sublist  three
> 2. Top level list two
> 3. Top level list three

which causes unwanted changes to the quoted markdown

[manuelpuyol]

cc @keithamus

[keithamus]

Great stuff!