Merge branch 'master' of https://github.com/cbhaley/calibre
Fix incorrect drag start caused by nicer cursor handling in the tag browser
Tag Browser: Use correct image for drag and drop even when item is showing the plus or minus icons
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Prevent unnecessary filesystem access when adding books to calibre
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E-book viewer: Add a keyboard shortcut to toggle the Table of Contents [Ctrl+T]
User Manual: Ensure the |lang| and |app| substitutions work everywhere

Also ensure that *all* .. include directives have their substitutions
properly processed, in case I add any more in the future.
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E-book viewer: Fix page turning by clicking in the margins in full screen mode (when displaying more than one page per screen) not working because of a Qt 5 behavior change.
Start work on completion popup for editor
Implement key based scrolling in the popup widget
Edit Book: More descriptive error message when saving fails because of a bad umask
A spot of refactoring
Fix Advanced search dialog not being sized correctly if the user selects a larger than normal interface font. Fixes #1378045 [advanced search box size problem](https://bugs.launchpad.net/calibre/+bug/1378045)
Update Sueddeutsche Zeitung mobil
OS X: Workaround for regression in Qt 5 that causes pressing the Esc key to close the entire window instead of the current completion popup

See https://bugreports.qt-project.org/browse/QTBUG-41806
Edit Book: Saved searches window: Remember the last used values for where to search and search direction
Update Smithsonian Magazine
Update WSJ