Imports of package code39

PathSynopsis
errorsPackage errors implements functions to manipulate errors.
github.com/boombuler/barcode
github.com/boombuler/barcode/utilsPackage utils contain some utilities which are needed to create barcodes
strconvPackage strconv implements conversions to and from string representations of basic data types.
stringsPackage strings implements simple functions to manipulate UTF-8 encoded strings.