Fix one remaining unsafe use of read_lock. Fixes #1348937 [Downgrade Lock Error: cant downgrade Lock Object](https://bugs.launchpad.net/calibre/+bug/1348937)
Update New Yorker
Edit Book: Fix cursor positioning not working when creating a new file from a template
Edit Book: Fix incorrect results when running replace all on marked text and more than one replacement is made. Fixes #1348941 [When applying the command Replace all with marked text, error happens](https://bugs.launchpad.net/calibre/+bug/1348941)