Cleanup the displaypics folder

[diederik]

KMess keeps a cache of received MsnObject data in ~/.kde/share/apps/kmess/{displaypics,useremoticons,winks}. This is needed to avoid redundant downloads. However, this cache is not cleaned up currently.

Some possible options:

• Set a maximum amount of MB's to use, remove oldest files afterwards
• Keep a list of recently used files, base removal on that.
• Examine which pictures are still used by /any/ contact in "kmessrc", base removal on that.
• Move the kmess accounts' display pictures into the displaypics/account@…/ folder, or somewhere else, to avoid having them all mixed up in the main data folder.