few helper/wrapper functions for simplistic level based logging

extracted from an older pandora box of such packages at abhishekkr/gol

• LogOnce(logfile, level, msg string), can be used without calling Start()

• Start() error, to be called at init/main before following Log Level functions to be used.

• Debug(msg string)

• Debugf(msgTmpl string, param ...interface{})

• Info(msg string)

• Infof(msgTmpl string, param ...interface{})

• Warn(msg string)

• Warnf(msgTmpl string, param ...interface{})

• Error(msg string)

• Errorf(msgTmpl string, param ...interface{})

• Panic(msg string)

• Panicf(msgTmpl string, param ...interface{})

• Level ("Debug", "Info", "Warn", "Error", "Panic")
• SaveAt (if to be persisted, log file path)
• Display (if to be printed on display, set to true)
• Persist (if to be persisted, set to true)

• SetGinLog(*gin.Engine) to be used for Gin to log json details for requests