Log Message:
neomutt: update to 20180622.

2018-06-22  Richard Russon  <rich@flatcap.org>
* Features
  - Expand variables inside backticks
  - Honour SASL-IR IMAP capability in SASL PLAIN
* Bug Fixes
  - Fix toggle-read
  - Do not truncate shell commands on ; or #
  - pager: index must be rebuilt on MUTT_REOPENED
  - Handle a BAD response in AUTH PLAIN w/o initial response
  - fcc_attach: Don't ask every time
  - Enlarge path buffers PATH_MAX (4096)
  - Move LSUB call from connection establishment to mailbox SELECTion
* Translations
  - Update Chinese (Simplified): 100%
  - Update Czech: 100%
  - Update German: 100%
  - Update Lithuanian: 100%
  - Update Portuguese (Brazil): 100%
  - Update Slovak: 59%
  - Reduce duplication of messages
* Code
  - Tidy up the mailbox API
  - Tidy up the header cache API
  - Tidy up the encryption API
  - Add doxygen docs for more functions
  - Refactor more structs to use STAILQ