TTL Deletion Hook

[four43]

I need to hook into when a cache item is removed from a TTLCache. It seems that expire() doesn't call it's local __delitem__() or the popitem() methods when an item is removed via expiration. Are you interested in a pull request for this feature?

[tkem]

popitem() is only called when items are removed when a cache is full to make room for new items. Items whose TTL expires just vanish into thin air, because you told them to do so after a certain time ;-)
Unless this is a popular use case I just haven't heard about so far, I'd prefer to not add any special handling for this.

[four43]

I was using this to managed locally cached files. I needed a hook to for when an item is deleted from the cache so I can remove them from my temporary directory. This library was too inflexible and I ended up just writing my own.

[momocow]

I met the same requirements, cached files, and came up with this library in mind. But it seems that I should implement my own cache to play with cached files.