Update build instructions for PoDoFo and ImageMagick
Fix metadata plugin to download metadata from OZON for website changes.  Fixes #1300383 [Searching metadata using Ozon.ru failed with error](https://bugs.launchpad.net/calibre/+bug/1300383)
pep8
...
DOCX Input: Fix error when converting document with nested frames. Fixes #1317543 [Conversion of a particular DOCX file](https://bugs.launchpad.net/calibre/+bug/1317543)
DOCX Input: Add support for cross references. Cross references that are used to insert hyperlinks are now converted into hyperlinks in the output document. Features to insert paragraph/page numbers are not supported.
Fix #1317635 [News fetching URL for NRC Handelsblad changes every day](https://bugs.launchpad.net/calibre/+bug/1317635)
version 1.36
Add build test for apsw
Edit Book: Add an entry to the context menu of the preview panel to open external URLs when a link is clicked on
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