Return nil if config value does not exist or is empty
Need return empty []string if config value is empty. split `“”` ==> []string{}, Not []string{“”}
ParseBool returns the boolean value represented by the string. It accepts 1, 1.0, t, T, TRUE, true, True, YES, yes, Yes,Y, y, ON, on, On, 0, 0.0, f, F, FALSE, false, False, NO, no, No, N,n, OFF, off, Off. Any other value returns an error.
DefaultString(key string, defaultval string) string // support section::key type in key string when using ini and json type; Int,Int64,Bool,Float,DIY are same. DefaultStrings(key string, defaultval []string) []string //get string slice DefaultInt(key string, defaultval int) int DefaultInt64(key string, defaultval int64) int64 DefaultBool(key string, defaultval bool) bool DefaultFloat(key string, defaultval float64) float64 DIY(key string) (interface{}, error) GetSection(section string) (map[string]string, error) SaveConfigFile(filename string) error
