Better fix for 65877, which doesn't require disabling "Tab means Down" in the completion box (#167135 says some people like that :-).
I think I found a solution that makes everyone happy: if there's only one entry then Tab autoselects the first entry
and completes again, allowing to use it like a shell for local files:  /hom<tab>dfau<tab>Docu<tab> for /home/dfaure/Documents.
If there's more than one entry, then Tab does "Down" as before.
CCBUG: 65877, 167135

svn path=/trunk/KDE/kdelibs/; revision=920743