This commit simplifies the Metrics class by using the new base module
from bStats. It also migrates to the new bStats config file that will
be used by plugins that integrate bStats. If a user disabled bStats in
the old config file, this setting will be copied to the new config file.
The existing Velocity logic was pretty optimistic, hoping the player connection would stay alive long enough to accept a connection to another server. Now, if we notice a read timeout on the server end, we'll treat the disconnect as "unsafe" and disconnect the player immediately.
I've added a configuration option to solve the issue in the way BungeeCord does it. This could cause issues with servers that extensively modify the server pipeline and could degrade the user experience, though. Let's try this more conservative and see if it helps,