Add BuildableStackedSlide.findTotalVertSize
Add BuildableStackedSlide.addChunk
BuildableStackedSlide: Add public-facing add methods
Make findTotalVertSize static and add annotation SafeVarargs
Implement BuildableStackedSlide.draw
Document BuildableStackedSlide
TextChunk: Correctly handle the center parameter
Change findTotalVertSize to take a List, not an ArrayList

Polymorphism is kinda important.