Log Message:
Updated calibre to 2.80.0.

- version: 2.80.0
  date: 2017-02-24

  new features:
    - title: "Add support for sideloading of KFX files created with the \ 
third-party KFX calibre plugin"

    - title: "Edit book: Allow drag and drop of image files, stylesheets \ 
and html files into the editor to insert the appropriate <img> and \ 
<link> tags and add the files to the book automatically."

    - title: "Kobo driver: Add support for updated firmware"

    - title: "Edit Book: Spell Check: If there are no suggestions fill the \ 
suggested word box with the original word."

    - title: "Viewer: add a shortcut (Ctrl+F11) to show/hide toolbars."

  bug fixes:
    - title: "PDF Output: Fix courier font not being rendered when \ 
converting on windows."

    - title: "E-mail delivery: Add a Message-ID header when sending emails. \ 
Reduces probability of mails sent from calibre being marked as spam"

    - title: "Save to disk: Fix path shortening being applied to entire \ 
save template even when saving to singe directory."

    - title: "Get Books: Update the Virualo and Publi store plugins for \ 
website changes"

    - title: "Viewer: Fix regression that caused slow opening of some books \ 
with missing font/css/image files"

    - title: "Viewer: Pressing Ctrl+F in fullscreen mode should show the \ 
controls."

    - title: "Edit book: Do not allow creating multiple new files whose \ 
names differ only by case."

    - title: "Viewer: Use heuristics to try to detect comics encoded as \ 
fixed layout EPUBs to ensure they are displayed as intended."

  improved recipes:
    - The Atlantic
    - The Financial Times

  new recipes:
    - title: Various new and improved Belgian news sources