SqueezeplayLuaLoggingLevels

There are four logging levels available in SqueezePlay, and they each have different roles

• ERROR - used when something is badly wrong, probably unrecoverable. The new logging code includes a stack trace on a log:error(). assert() should use this too.
• WARN - used for a significant, unexpected failure. So for example a server disconnect would not be a warn.
• INFO - used for significant, expected events. Like current server connect/disconnect, switching players, streaming a new song.
• DEBUG - used for everything else, including log messages used during development.