Add CSIDL_PROFILE constant
A more complete fix for non ascii usernames on windows when using the export file dialog. See #1298071 ([Edit book]: Crash exporting image)
Make ExclusiveFile thread safe on Unix (use flock instead of lockf)
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Edit Book: Fix an error when running the Check Book tool on files with empty <style> tags. Fixes #1320459 [Private bug](https://bugs.launchpad.net/calibre/+bug/1320459)
Add .ibook*s* as a recognized ebook format as well
Start work on Live CSS view