Adds /paper command for reloading the paper config.
Closes GH-639
Per-world config logging has been removed in favor of all or nothing
logging for all paper settings. I don't believe it was used enough to
warrant maintaining. If this is not the case it should be possible to
re-add it.
As of 1.8, it is possible to customize worlds beyond what these settings
allow using a Customized world type, however, this is still useful for
non-Customized worlds and Nether worlds.