hidden directory crash - analysis..

[Maks Orlovich]

> The attached patch does this. However, it now becomes very obvious that
> the "show hidden files" menu-option has no effect on the dirtree. I'm not
> sure if there is a simple way to make it follow the other view in this
> regard, but otherwise I would like to suggest to simply disable showing
> dotfiles in the directory tree and be done with it. (also attached)

Well, either one should be preferrable to crashing, obviously..  And it
doesn't seem like enabling the dot files in the treeview was at all easy to
do anyway, seeing how much difficulty everyone had reproducing it..