Fixed patch :)
Run Player move synchronous to avoid problems
Use the real player name on stats book creation to avoid problems with plug-ins changes the display name/player list name.
Check if the book has an author before trying to compare the author with "Statistics".

Fixes NPE if you open an book with no author (created by another plugin or with /give 387)
Only get the metadata if the item is an written book

Fixes EventException if you right click with an normal book.

Actually I have no idea why an book open event is fired if you right click wit an normal book item..................