Test mixed line height with varied alignment.
Remove unused alignment function.
Update changelog on vertical alignment.
Implement vertical alignment.
BREAKING: Boxes now generate struts (CSS), which can make a line taller
than is necessary to contain its fragments.
Do not pass around unnecessary data.
Store parent text options in ResolvedBox.
This is required for vertically aligning the box with its parent.
Add options for vertical alignment.
Separate vertical alignment from horizontal positioning.
Store vertical offsets inside ProtoFragment.
Intended to make these offsets manipulable during layout.
Add internal structure for vertical offsets.
Use more specific name for the LineHeight typeclass.
Fix internal link to non-existent identifier.
Clarify that fragmentContentRect is unstandardised.
Set release date for v1.2.0.0
Add content rect to Fragment.
Add helper function to strut empty boxes.
Test preservation of lines with boxes.
Test boxes with no text or only a space.