Supply context to shutdown-on-error error fn

Prior to this commit, if you registered an on-error handler with
the `shutdown-on-error` function from the shutdown service,
the on-error fn had to be a no-arg fn.  This gave you no way
to access your service's context if you needed to.

This commit changes the behavior so that the on-error fn must
be a one-arg fn that accepts the service context map as its
argument.
Set logging context on testutils atom appender
Cleanup / fixes based on PR feedback

This commit includes:

* removed TODO commented plugin/etc initialization code
* README.md: s/hole/hold
* README.md missing paren
* change namespace aliases in core away from using single-letter pattern
* rename run-lifecycle-fn to run-lifecycle-fn!
* change 'sid' variable names to 'service-id'
* change tests that used `partial` to reference service functions; they now just reference the service