Adding test cases for:

    Adding test cases for:
        1) Arrowing up or down to an empty list item skipped the list item
        2) Deleting the content of a list item made it so you could never get the cursor inside the empty item

        * editing/selection/move-by-line-002-expected.png: Added.
        * editing/selection/move-by-line-002-expected.checksum: Added.
        * editing/selection/move-by-line-002-expected.txt: Added.
        * editing/selection/move-by-line-002.html: Added.
        * editing/deleting/delete-listitem-002-expected.checksum: Added.
        * editing/deleting/delete-listitem-002-expected.png: Added.
        * editing/deleting/delete-listitem-002-expected.txt: Added.
        * editing/deleting/delete-listitem-002.html: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@12456 268f45cc-cd09-0410-ab3c-d52691b4dbfc