Our test cases spew a lot of files and directories around $TMPDIR. Make more
thorough use of the testing package's TempDir methods to ensure these are
cleaned up.
In a few cases, this required plumbing test contexts through existing helper
code. In a couple places an explicit path was required, to work around cases
where we do global setup during a TestMain function. Those cases probably
deserve more thorough cleansing (preferably with fire), but for now I have just
worked around it to keep focused on the cleanup.
This is a very small change, but removes a method from the
`service.Service` interface (a win!) and forces callers to explicitly
pass loggers in to objects during construction rather than (later)
injecting them. There's not a real need for this kind of lazy
construction of loggers, and I think a decent potential for confusion
for mutable loggers.
The main concern I have is that this changes the constructor API for
ABCI clients. I think this is fine, and I suspect that as we plumb
contexts through, and make changes to the RPC services there'll be a
number of similar sorts of changes to various (quasi) public
interfaces, which I think we should welcome.
