show parents in publish-index page

[kanduvisla]

Hi,

I made some modification to your pages-field extension. Now it shows the parent page in the publish-index page. It's a bit tricky with sorting however. It does sort, but in different levels. This is a limitation because of how Symphony handles the building of the sorting SQL-query (the buildSortingSQL()-function), but it's as good as it gets.

It sorts for each level like this:

a
b
c
a / a
a / b
a / c
a / a / a
a / a / b
b / a
b / b
c / a
c / b

Please let me know what you think of this. Is it something you can use?