~jaro/balkon

ref: c4368fbcb56f06524d52fbdbbb984be772bb1f8c balkon/.golden/czechHelloParagraph d---------
Add ignored prefixes and suffixes to test data.

This ensures that implementation does not rely on the texts having zero
offset inside their byte arrays.
Use top edge for placing lines.
Calculate "normal" line height and pen position.
Upgrade Fragment to contain pen position.
Implement "plain" interface.