For EAN13 and similar barcodes separately set the guard bar height

[IzuMan0x]

Please add the ability to control the data bar height (shorter bars) and the guard bar height (longer bars).

This is an image from a barcode designer where you can separately set the height of the guard bars and data bars.

[terryburton]

Fixed with 5d8b2b8 which introduces guarddescent=N where N is a multiple of the X-dimensions.

Will be documented in due course.