Add a fourth character to the second column of the "typed output format"
to indicate whether the value results from a volatile or persistent metric
('V' or 'P' characters respectively). A persistent metric means the value
could possibily be preserved across reloads by leveraging a shared memory
between multiple co-processes. Such metrics are identified as "shared" in
the code (since they are possibly shared between multiple co-processes)
Some reg-tests were updated to take that change into account, also, some
outputs in the configuration manual were updated to reflect current
behavior.
When threads are enabled and running on a machine with multiple CCX
or multiple nodes, thread groups are now enabled since 3.3-dev2, causing
load-balancing algorithms to randomly fail due to incoming connections
spreading over multiple groups and using different load balancing indexes.
Let's just force "thread-groups 1" into all configs when threads are
enabled to avoid this.
No less than 30 tests were missing timeouts, preventing them from being
started with zero-warning. Since they were not supposed to trigger, they
have been set to 30s so as never to trigger, and now they do not produce
any warning anymore.
Define a simple regtest to check stats-file loading on startup. A sample
stats-file is written with some invalid values which should be silently
ignored.
