I cannot find an option to print line numbers, is there a way to do this, and if not will it be added to a latter version?

It will be added in the next release. For now, you can insert line numbers before printing in the text using Fill Column Block command from the Edit menu.

Cool, do you know when the next release is due ?

Two years have passed while we await this feature.
Is there going to be a next version??

Version 3.2 will print line numbers.