Ebookconverter

- normalize capitalization of "eBook"
- only send notification for CRITICAL errors 33

- notifications, both success and problem alerts, are now sent only to the whitewasher.
- notification texts have been cleaned up to be more readable and more friendly
- refactored PUBLIC, FILES, FTP into libgutenberg>=0.10.15
- CACHDIR and FILESDIR now need to be set in ~/.ebookmaker as well as ~/.ebookconverter, Probably these belong in an environment variable.

- added documentation for commands
- add checking that a source file exists
- refactor filesize checking to remove CRITICAL messages when a build is skipped
- update tests

- Adds UpdateWriter. It scans source files for metadata headers and adds to the database. Currently only looks for 'Credit:' or 'Produced by:'.
- `.xhtml` added to parseable file extensions
- stop producing kindle.noimages unless asked to
- add a "generic" file name for Writers that don't write (Twiter, Facebook, Update)

- when the html file is large (>16M), in most cases we don't really want to make an EPUB or a MOBI. Making the MOBI can take hours with our current infrastructure. Changed the source file size filters so these formats are not made.
- when the source EPUBs are >32M, only old-format MOBIs are not made.
- add jekyll script
- stop trying to store qr codes in databaseta from backup workflow files
- add script to load metadata

- production directory moves from ~/converter to ~/ebookconverter to accomplish the python version migration.