How I Made PDF Table Rendering 95% Faster in an Afternoon

"That's tagging a 50k cell table almost 40x faster. Not bad for an afternoon's work, eh?"

Commits that made it happen:

https://github.com/itext/itext-java/commit/71451319ebb9463d2...

https://github.com/itext/itext-java/commit/b50c34e14f012993f...

https://github.com/itext/itext-java/commit/b6b212971e285a4a8...

https://github.com/itext/itext-java/commit/0626cd422a275ac40...

Always nice to see some digging into algorithms, and low level details.

Also, bonus points for speeding up tagging, and helping those who need accessible PDFs!