Headfile Cleanup should wait for max file size

[tm-ms]

If the head file is still pretty tiny (e.g. 2 kB with a 8 MB max file size) but already contains a lot of logical gaps (e.g. the same collection is stored multiple times), it is currently aggressively resolved into a new head file. This generates an unnecessary large amount of tiny head files.

It would be smarter to let the head file reach its max file size, first, before resolving it. But then again, that was the point of not cleaning up head files in the first place. Maybe that has to be changed back to not cleanup up head files or the condition for head files has to be made smarter or something like that.

Not remotely critical, but a little annoying.