Fix #1360547 ["Legacy" window title](https://bugs.launchpad.net/calibre/+bug/1360547)
Use the full formatter for the catalog templates so the full template language and all custom columns can be used.

I have tested this in epub and mobi and it works as far as I can tell. Unfortunately this code is very complicated so there may be problems. We will see...
Fix the unified title and toolbar on Mac tweak causing calibre to fail to work because of a bug in PyQt5
Fix #1360547 ["Legacy" window title](https://bugs.launchpad.net/calibre/+bug/1360547)
Fix the unified title and toolbar on Mac tweak causing calibre to fail to work because of a bug in PyQt5
Workaround for Qt 5 bug that prevents using the return key to edit table cells in the main book list

https://bugreports.qt-project.org/browse/QTBUG-40938
E-book viewer: Fix navigating to a bookmark not updating the displayed page number. Fixes #1360621 [(ebook-viewer) weird behaviour dealing with current page in ePub](https://bugs.launchpad.net/calibre/+bug/1360621)
Linux: Disable the optional system tray icon in linux because of bugs in the system tray icon implementation in Qt 5 on linux. See #1360652 (calibre 2.0 system tray icon missing, cannot quit)

https://bugreports.qt-project.org/browse/QTBUG-31762
pep8
Prevent calibre from installing or running on Windows XP as there have been many reports of Qt 5 crashing on Windows XP and Windows XP is now no longer supported by Microsoft.
Possible fix for --detach crash on some linux systems

Do not use file objects for redirecting the std streams as they could be
garbage collected closing the streams. Also redirect stdin. I dont
really expect either of these to fix the issue, but it's a start.
Use C code to redirect standard I/O streams for --detach and --daemonize
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Fix regression in calibre 2.0 that caused crashes when using drag and drop to re-order virtual library tabs
ebook-viewer: Handle --open-at using a localized string (, instead of .  for decimal separator)
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Add translatable strings from the QT font dialog
pep8