InMemoryLog entries on repeated counter perf runs keep on growing

[franz1981]

While running single node repeated tests with InMemoryLog performance degrades over runs because LogEntry on InMemoryLog::entries keep on growing.

[belaban]

InMemoryLog is supposed to be used only by unit tests. However, we could replace entries with ArrayRingBuffer if you wanted

[franz1981]

I would rather disable to set it by user(s) if is not well-behaving - and just it to exist on test packages

People that doesn't want to fsync can just use the file log on tmpfs without fsync

[belaban]

ah, ok, good idea. I'll move it to the test package then!

[belaban]

This means #153 is moot then?

[belaban]

On second thought, InMemoryLog might be useful to test a setup that doesn't write to disk, ie. when testing RTTs. I'll leave InMemoryLog where it is and rather implement this issue and #153. Not very high prio, though...