Code review comment for lp://staging/~bryce/gtg/scheduling

Interesting but I fail to see the usefulness of "Start today". I think that this patch should come along with renaming "start date" to "defer to" or something similar

Traceback (most recent call last):
  File "/home/ploum/gtg/GTG/taskbrowser/tasktree.py", line 604, in scroll_to_task
    self.scroll_to_cell(model.get_path(iter),
TypeError: iter should be a GtkTreeIter