Update El Correo
...
Fix over-aggressive caching causing multiple cover grid emblem rules to not work. Fixes #1352005 [Emblems in cover grid don't work with multiple rules](https://bugs.launchpad.net/calibre/+bug/1352005)
Add a reference to the plugin object in the Tool class and also improve
documentation a little
...
...
...
...
E-book viewer: Make the Table of Contents panel a dockable window so it can be moved around and even made into a separate floating window

Also refactor the viewer's ui code to not use Qt Designer.
Port compiling of .ui forms
Port imports
Port build script for building PyQt extensions to PyQt5
Port the progress indicator extension to PyQt5
Allow controlling PyQt5 import path via the env var PYQT5_IMPORT_PATH
faster builds
Get rid of the PyQt4 string from everywhere
Port: setMargin() reset() QStringList()

setMargin(): QLayout no longer has a setMargin() function, replace with
setContentsMargins()

reset(): QAbstractListModel no longer has reset(), replace with
beginResetModel(), endResetModel()

QStringList: No longer exists, a simply python list of strings works
instead
Fix mouse wheel not working in diff view
Port coffeescript compiler
Add note about headless Qt QPA plugin