Originally, syz-manager confusingly logs corpusSignal as "cover".
Change syz-manager's logging to output corpusSignal, corpusCover
and maxSignal.
Add a field in Stats to store maxSignal.
Use a random subset of syscalls/corpus/coverage for each individual VM run.
Hypothesis is that this should allow fuzzer to get more coverage
find more bugs in saturated state (stuck in local optimum).
See the issue and comments for details.
Update #1348
Move work with hub into a separate file and fully separate
its state from the rest of the manager state.
First step towards splitting manager into managable parts.
This also required to rework stats as they are used throughout the code.
Update #538
Update #605
