patch: Depot remembers selected line

[Dwachs]

.. the title says it all: depots remember now the line, which was selected the last time, when the depot was visited. I had the feeling that this property was implemented some time ago but disappeared in newer versions.

[gerw]

That's very nice and usefull!

[prissi]

Before Depot was static => this was not good. But your patch is fine. Include in r2103.