This is the final release for 1.14.x
* Fix header in text pages not being localizable
* Thread-safety fixes in API methods
* Entries will only show up in the book if they've successfully been built. This fixes many crashes where you have a half-baked book due to earlier loading errors. Please check the log if you see missing entries in your book.
* Category loading errors will now halt loading of the book and show up in the log
* Label and highlight buttons properly so they can be selected with the tab key (and the narrator can read their names)