Fixing the rendering of the children content and add dashes for hierarchy separating.

Relate to issue #2541 

I fixed the problem with the partial hierarchy tree but i found another bug: when i checked the fix i applied to the rendering of the tree i noticed that the ordering of terms is not reflected until i clearing the cache.

This is a problem with the entity cache module that did not clear the cache of the taxonomy terms when changing the order of terms. I couldn't re produced that on a clean installation of Drupal so i'm assuming that this is specific use cace for OS. I added a custom submit handler for that.