Enhancement #1360550 Shortcut to template editor
Workaround for Qt 5 regression that prevented the keyboard shortcuts for the various Similar books actions from working
Add a new tool to easily test templates. Go to Preferences->Toolbars to add the tool to one of the calibre toolbars. Fixes #1360550 [Shortcut to template editor](https://bugs.launchpad.net/calibre/+bug/1360550)

Merge branch 'master' of https://github.com/cbhaley/calibre
Small improvement on template tester messages.
Enhancement #1360766: show plugboards for disabled devices and allow entering plugboards when no metadata writer is enabled.
Preferences->Metadata plugboards: Show plugboards for disabled devices and formats whose metadata writer plugins have been disabled. Fixes #1360766 [display plugboards with disabled plugin](https://bugs.launchpad.net/calibre/+bug/1360766)

Merge branch 'master' of https://github.com/cbhaley/calibre
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OS X: Fix background jobs stealing input focus if they require the use of hidden browser
Proper OS X command line tools path
Fix #1360806: allow book.smart_update to copy "null" (Unknown) author information to the destination if the destination author and author_sort values are null. There is a small performance hit if the source of the copy is null, which fortunately is rather rare. This change better supports non-null author_sort values associated with null author values.
Workaround for crash when running job (conversion to PDF or MOBI/reading metadata from epub without cover) that requires Qt WebKit on Ubuntu. Fixes #1360693 [Ubuntu: Import EPUB, Metadata Error](https://bugs.launchpad.net/calibre/+bug/1360693)

See https://bugreports.qt-project.org/browse/QTBUG-40946
Fix #1360806 [{author_sort} ignored (when saving and in plugboards) when book has no author](https://bugs.launchpad.net/calibre/+bug/1360806)

Merge branch 'master' of https://github.com/cbhaley/calibre
E-book viewer: When right clicking on an image to view it in its own popup window, fix the rotate button not working correctly with the zoom buttons
Possible fix for crash on some linux systems in Qt 5 with --detach

Do the fork() before loading any Qt modules.
Merge remote-tracking branch 'upstream/master'