Fix crash when using %e with strftime on windows

Fixes #1206705 [strftime crashes under Windows with %e](https://bugs.launchpad.net/calibre/+bug/1206705)
Get Books: Add plugin for cdp.pl

Merge branch 'stores' of https://github.com/t3d/calibre
Move mirror domain name to fosshub.com
Nicer interface to library metadata backups
...
...
...
newdb: Fix duplicates during adding creating blank book record

Fixes #1206830 [Problem when adding duplicate title](https://bugs.launchpad.net/calibre/+bug/1206830)
Fix the issue of renaming user categories to the same name it already has resulting in deletion of the category (see https://bugs.launchpad.net/calibre/+bug/1207131)
newdb: Fix default value for identifiers is mutable
Merge branch 'master' of https://github.com/brandizzi/calibre

Fix renaming a user category to the same name it already has erases the
user category. Fixes #1207131 [Renaming a user category to the same name it already has erase this same user category](https://bugs.launchpad.net/calibre/+bug/1207131)
QDateTime->datetime faster and more robust

Fix editing of book metadata failing when its timestamp is out of range
for the system. Fixes #1191599 [Cannot edit simple ebook metadatas](https://bugs.launchpad.net/calibre/+bug/1191599)
Update PC World
Avoid unnecessary tracebacks when backing up metadata for deleted books
newdb: get_metadata() should have sorted formats list in mi.formats
Download tags from Amazon

When downloading metadata from Amazon, convert the amazon categories into
tags. You can turn this off by going to Preferences->Metadata download
and configuring the Amazon source. Fixes #1206763 [[Enhancement] Get tags from Amazon](https://bugs.launchpad.net/calibre/+bug/1206763)
Append and modify CSS when sending epubs to Kobo devices

This allows users to have a "kobo_extra.css" file in the root of their
device containing CSS rules. This will be appended to all stylesheets in
the epub. As well, if the extra rules contain an @page rule, any
existing @page rules will be stripped from the stylesheets. Finally, if
any of the extra rules include "widows" and "orphans" settings, these
are stripped from the rules in the stylesheets.
Kobo driver CSS modification should use mimetype
pep8 cleanup of kobo/driver.py

Kobo driver: Add an option to modify the styling in books being sent to
the device, based on a template on the device. Fixes #1207151 [Append and modify CSS when sending epubs to Kobo devices](https://bugs.launchpad.net/calibre/+bug/1207151)
Unused import