Automatic expansion of column widths is excessive on symlinks

Symlink targets can be quite lengthy. In combination with the display for the type of symlinks as "link to ../../../.git/annex/objects/some-sha512-hash/some-sha512-hash", this easily leaves users with the impression that columns to the right of "Type" vanished.

I suggest that columns be either scaled back to a reasonable width when large widths are not required any more, or that there be a sanity limit to the column widths (say, half the window width?).