Log Message:
Updated neomutt to 20170907.

2017-09-07  Richard Russon  <rich@flatcap.org>
* Contrib
  - Add guix build support
* Bug Fixes
  - Only match real mailboxes when looking for new mail
  - Fix the printing of ncurses version in -v output
  - Bind editor \<delete\> to delete-char
  - Fix overflowing colours
  - Fix empty In-Reply-To generation
  - Trim trailing slash from completed dirs
  - Add guix-neomutt.scm
  - Fix setting custom query_type in notmuch query
* Website
  - New technical documentation LINK
  - Improve Gentoo distro page
* Build
  - Better curses identification
  - Use the system's wchar_t support
  - Use the system's md5 tool (or equivalent)
  - Clean up configure.ac
  - Teach gen-map-doc about the new opcode header
* Source
  - Rename functions (snake_case)
  - Rename constants/defines (UPPER_CASE)
  - Create library of shared functions
  - Much tidying
  - Rename globals to match user config
  - Drop unnecessary functions/macros
  - Use a standard list implementation
  - Coverity fixes
  - Use explicit NUL for string terminators
  - Drop OPS\* in favour of opcodes.h
* Upstream
  - Fix menu color calls to occur before positioning the cursor
  - When guessing an attachment type, don't allow text/plain if there is a null \ 
character
  - Add $imap_poll_timeout to allow mailbox polling to time out
  - Handle error if REGCOMP in pager fails when resizing
  - Change recvattach to allow nested encryption
  - Fix attachment check_traditional and extract_keys operations
  - Add edit-content-type helper and warning for decrypted attachments
  - Add option to run command to query attachment mime type
  - Add warning about using inline pgp with format=flowed