Make the current logging class a static variable with accessor functions, rather than exposing the global.  Change the core logging method to match the existing LCLNSLogging_RK class which is out there; that class could probably be used as-is for the logging class.  Move the RKLogging definition to the logging config header; it has to be there since the lcl typedefs are only defined by the lcl headers (which import that config file), which need to be defined before we can declare the RKLogging protocol, which in turn should be defined before we use that in the core logging macro definition, which I think must be defined before the rest of the lcl definitions.  So I'm not sure we can move it elsewhere and still use the lcl typedefs.  Moved the implementations to RKLog.m.