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
RPC package does excessive caching per connection,
so if a larger object is ever sent in any direction,
rpc connection consumes large amount of memory persistently.
This makes manager consume gigs of memory with large
number of VMs and larger corpus/coverage.
Make all communication done in very limited batches.