bug#10323: 24.0.92; docstring diary-date-forms

[Roland Winkler]

> Actually, this is not completely true either, and it becomes
> relevant if one wants to indent the diary entries for which the
> `backup' mechanism of diary-european-date-forms applies. If one
> has the diary entries
> 
> 18/12/2011$  foo bar
> 18/12/2011   foo baz
> 18 December  foo bar
> 
> the first two entries are indented as one might expect it; yet the
> third one is not indented (i.e., with `backup' all whitespace
> characters following immediately the date become part of the date)

To avoid misunderstandings: Here I was talking about how
diary-fancy-display displays the above diary entries.
This uses diary-date-forms.

Roland