This is hard and finicky to test, so there's unfortunately not a clear
way to get 100% test coverage in cherrypy_start. However, that
function is only used in the test suite and the standalone
nilmdb-server script, not in production (which goes through wsgi and
skips all this cherrypy server stuff entirely).
Non-embedded mode is not used in the test suite or wsgi server;
it was an option in the standalong nilmdb-server script, but it's
really not necessary, and removing it gets rid of some untested
code.
simplejson was there for python <= 2.6 compatibility.
It's not needed now, and installing it with pip can lead to segfaults
because pip is dumb.
(see e.g. https://github.com/simplejson/simplejson/issues/114)