Truncate directory listings

[DaneGardner]

We need to truncate directory listings to the top 1000 or so, just in case a user winds up in a directory with a million files, which would take forever to stat each one, and would take forever to transmit to the client, and would take forever to deal with in the RemoteFileDialog's model/view memory.

[DaneGardner]

We should notify the client that it's only a selection of the total number of files, that have been returned so the user can be notified.

[DaneGardner]

I did some testing on the number of files that could saturate the dialog... and I actually didn't find an upper limit. In a VM on a 4-disk RAID0, 32k files only took 3 seconds for the server to retrieve and begin sending. The client only took an additional 3 seconds to deal with the load and pass it into the widget before sorting and displayed to the user.

I think that if anybody expects more out of this system, they're crazy... however I do think that it's possible to have an accidental stat of all the files in a very large database, and this should really be implemented eventually.