This is simply a change of read_chunk() protocol, where a response of
read_chunk() becomes list of written bytes along with checksum. All
related code including repair is changed as such. This is to pass all
tests and not actually supporting partial chunks.
The FLU psup starts the chain manager in active mode by default
(as it should for normal run-time operation.) By adding the
{active_mode, false} tuple to the options list, we can
tell the chain manager that it should be explicitly manipulated
during tests.
PULSE managed to create a situation where machi_proxy_flu_client1
would appear to fail a remote attempt to write_projection. The
client would retry, but the 1st attempt really did get through to
the server. So, if we hit this case, we try to read the projection,
and if it's exactly equal to what we tried to write, we consider the
op a success.
Ditto for write_chunk.
Fix up eunit test to accomodate the change of semantics.
Introduce machi_flu_psup:start_flu_package/4 as a way to start all
related FLU processes
* The projection store
* The chain manager
* The FLU itself
... as well as linked processes.
http://www.snookles.com/scotttmp/flu-tree-20150430.png shows one FLU
running, "a". The process registered "a" is the append server,
"some-prefix" for the sequencer & writer for the current <<"some-prefix">>
file, and a process each for 3 active TCP connections to that FLU.
