save link to last number in a variable instead of finding it out again and again
use mobile page pt.1
add masthead picture and fix feed name
Edit book: Fix option to disable showing the character before cursor not working
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Make the installer run non-interactively with installation dir specified via environment variable
RTF Output: Fix invalid RTF being produced when the text contains a double backslash. Fixes #1268118 [epub converted produces invalid .rtf file](https://bugs.launchpad.net/calibre/+bug/1268118)

Also updates to various Get Books plugins

Merge branch 'master' of https://github.com/user-none/calibre
Various Russian news source by bug_me_not
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Nicer error message on failure
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py3 compat
Add a debug line in hopes that it will help (eventually) find why in some cases the incorrect series sort values are being sent to CC.
Allow the empty string when writing to bool custom columns. Bulk edit uses the empty string for None, at least in this case.
Merge branch 'master' of https://github.com/cbhaley/calibre
Fix test failing because of change in behavior of dateutil module
Merge branch 'master' of https://github.com/t3d/calibre
Edit book: Add an option to automatically beautify individual files whenever they are opened for editing. Look under "Editor Settings" in the Edit Book Preferences.
Update Spektrum