It allows to display hierarchical data in much less horizontal space than
getCategoryChildLogicalPathItemList.


example :

getCategoryChildLogicalPathItemList :
Foooooooo
Foooooooo/Baaaaaaaar
Foooooooo/Baaaaaaaar/Baaaaaaaaz
Foooooooo/Baaaaaaaar/Baaaaaaaaz/Quuuuuuuux

getCategoryChildIndentedTitleItemList :
Foooooooo
  Baaaaaaaar
    Baaaaaaaaz
      Quuuuuuuux


Possible improvements :
for now, I just add some " " before the title, but it breaks the mozilla
  "type and search" feature. Maybe it is possible to use CSS to get the same
  visual result ...


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@4253 20353a03-c40f-0410-a6d1-a30d3c3de9de