[PATCH] fix #47996

[Waldo Bastian]

>Coolo said fix it, so the attached patch fixes #47996, please review. I added
>a method checkUpdate(dir) that checks if dir should be updated or delayed.
>slotFileDirty now delays all the update events it gets by 500ms (that's the
>STAT frequency) and drops all other events for the same file during this
>time. I don't know why FAM is flooding KDirLister that much but during this
>500ms delay I got 100 (!) FAM events. Phew. The only bad thing is that my
>patch adds another QDict (the timers) to KDirListerCache. Ok, it's not too
>much, but anyways, it's additional bloat because of FAM going mad :-/
>
>Also, slotFileDirty was the only method that updated files and directories
>even if they were in itemsCached. Fixed.
>
>Will commit tomorrow (damn, I hate to work at night... will be really tired
>tomorrow :( )

I think this should eventually be handled in KDirWatcher, possibly 
with an increasing backoff-period. (After 3.1)

Cheers,
Waldo