The keys used are:
!: modified feature, -: deleted feature, +: new feature
+1.8.0 (2017-02-24):
+
+ - $locale has been removed. Mutt now respects the LC_TIME setting
+ instead. See also $attribution_locale.
+ + $attribution_locale can be used to override the date formatting in
+ attribution strings. When unset, Mutt will use the locale
+ environment, but note the default value of $date_format has a
+ leading '!' which says to use the C-locale.
+ ! Message-id and mail-followup-to headers are now preserved for recalled
+ messages.
+ + <unsidebar_whitelist> added to complement <sidebar_whitelist>.
+ ! The pager position is reset to the top when toggling header-weed.
+ ! IMAP messages moved to $trash via server-side copy are marked as read.
+ + <root-message> jumps to the root message of a thread.
+ ! Piped text attachments are charset converted.
+ + Added %F to $attach_format, to show the content-disposition filename.
+ %d will fall back to %F which will fall back to %f.
+ + <rename-attachment> allows an attachment name to be changed, without
+ modifying the underlying file's name.
+ ! The user's muttrc will additionally be searched for in
+ $XDG_CONFIG_HOME/mutt/.
+ + Compressed mbox and mmdf files are now supported via open-hook,
+ close-hook, and append-hook. See contrib/sample.muttrc-compress
+ for suggested settings.
+ + When $flag_safe is set, flagged messages cannot be deleted.
+ + The '@' pattern modifier can be used to limit matches to known aliases.
+ + <mark-message> creates a hotkey binding to a specific message. The hotkey
+ prefix is specified via $mark_macro_prefix.
+ + <setenv> and <unsetenv> can be used to add/remove environment variables
+ passed to children.
+ ! OpenSSL certificate verification has been reworked to suppport alternative
+ chains.
+ + $uncollapse_new controls whether a thread will be uncollapsed when a new
+ message arrives.
+ ! $to_chars and $status_chars now accept multibyte characters.
+ + <subjectrx> allows replacing matching subjects with something else.
+ This can be used to declutter subject lines in the index.
+ + <edit-label> can be used to add, change, or delete a message's X-Label.
+ ! Pattern expressions with ~y support label tab completion.
+ + LMDB backend support for the header cache.
+ + Kyoto Cabinet backend support for the header cache.
+
1.7.2 (2016-12-04):
! Bug fix release. No features were modified or added.