Avoid nesting in configuration of Config struct
Avoid nesting in configuration of Config struct

To do this, copy fields by hand into a newly formed MiniConfig instead
of using struct composition, because Struct composition requires
nesting in the notation for initialization otherwise, forcing a
consumer to study both MiniConfig and Config to use the API, which
seems silly.

Signed-off-by: Daniel Farina <3d0f3b9ddcacec30c4008c5e030e6c13a478cb4f@heroku.com>

heroku/logplexc,logplex/logplexc