This update for calibre provides version 2.81.0 and fixes the following issues:

- New Features
+ Amazon metadata download: Allow downloading amazon metadata from multiple sources. You can now configure the Amazon
plugin via Preferences->Metadata download to use either the amazon servers, or various search engine caches to
get the metadata. Should help with the recent CAPTCHA problems when downloading metadata from amazon.
+ Kobo driver: Add support for new firmware.
+ Edit Book: Spell Check dialog: Always add the original word as one of the spelling corrections, so that small edits
to the word can be made easily.
+ Edit Book: Saved searched Dialog: Allow re-arranging the saved searches using drag and drop.
+ Implement auto update of builtin metadata download plugins, just as for recipes and Get Books plugins. Needed as the
websites they get data from often change.
+ Edit Book: When inserting full screen images, use the actual image dimensions in the generated SVG code, when
available.
+ Linux installer: Check that the umask is suitable before running the installer. Should fix breakage on systems where
users have changed the user umask but neglected to also alter it for sudo.
+ Bulk metadata edit: Remove the control to delete specific formats as it is redundant. This functionality is already
present by right clicking the Remove books button.
+ Add support for sideloading of KFX files created with the third-party KFX calibre plugin.
+ Edit book: Allow drag and drop of image files, stylesheets and html files into the editor to insert the appropriate
and tags and add the files to the book automatically.
+ Edit Book: Spell Check: If there are no suggestions fill the suggested word box with the original word.
+ Viewer: Add a shortcut (Ctrl+F11) to show/hide toolbars.
+ OS X/Linux: Show an informational popup message when an Android device is plugged in that needs the user to tap
Allow for the connection to work.
+ Conversion: Log options that are different from the defaults separately, for easy reference.

- Bug Fixes
+ TXT Input: When detecting the encoding of txt files only use the first four kilobytes of text. Fixes excessively
slow conversion of very large text files.
+ Get Books: Fix price not being displayed for books from Amazon dues to website changes.
+ GetBooks: Update Google Books plugin for website changes.
+ E-book viewer: Fix slow startup when recently opened files are on a slow/malfunctioning networked filesystem.
+ Google metadata download: Fix metadata not being found when the title of the book includes a sub-title.
+ Improve downloading of covers from the google books metadata source.
+ News download: Fix a bug that could cause a crash when downloading an SVG image.
+ Edit book: Fix a regression that caused pasting copied text from programs that generate both HTML and plain text
when copying to paste the HTML in preference to the plain text.
+ E-mail delivery: Add a Message-ID header when sending emails. Reduces probability of mails sent from calibre being
marked as spam.
+ Save to disk: Fix path shortening being applied to entire save template even when saving to singe directory.
+ Get Books: Update the Virualo and Publi store plugins for website changes.
+ Viewer: Fix regression that caused slow opening of some books with missing font/css/image files.
+ Viewer: Pressing Ctrl+F in fullscreen mode should show the controls.
+ Edit book: Do not allow creating multiple new files whose names differ only by case.
+ Viewer: Use heuristics to try to detect comics encoded as fixed layout EPUBs to ensure they are displayed as
intended.
+ Conversion: Fix regression that broke conversion of some epub files when using the 'Remove first image' option.
+ Get Books: Update Kobo plugin for website changes.
+ Windows MTP driver: Fix error when enumerating device storage not being reported during debug device detection.
+ Tag Browser: When dragging and dropping a book onto a series increment the series number.
+ Fix crash when generating covers with Qt 5.8 on linux.
+ Fix Get Books result list and jobs list not being populated on Qt 5.8.
+ Fix importing rules in the coloring/icon rules dialog not enabling the apply button.