Updated notmuch to 0.23.

Notmuch 0.23 (2016-10-03)
=========================

General (Xapian 1.4+)
---------------------

Compiling against Xapian 1.4 enables several new features.

Support for single argument date: queries

  `date:<expr>` is equivalent to  `date:<expr>..<expr>`.

Support for blocking opens

  When opening a database notmuch by default will wait for another
  process to release a write lock, rather than returning an error.

Support for named queries

  Named queries (also known as 'saved searches') can be defined with a
  `query:name` format. The expansion of these queries is stored in the
  database and they can be used from any notmuch client.

Library
-------

Message property API

  libnotmuch now supports the attachment of arbitrary key-value pairs
  to messages. These can be used by various tools to manage their
  private data without polluting the user tag space. They also support
  iteration of values with the same key or same key prefix.

Bug fix for `notmuch_directory_set_mtime`

  Update cached mtime to match on-disk mtime.

CLI
---

Support for compile time options

  A group of `built_with` keys is now supported for notmuch
  config. Initial keys in this group are `compact`, `field_processor`,
  and `retry_lock`.

Dump/Restore support for configuration information and properties

  Any configuration information stored in the database (initially just
  named queries) is dumped and restored. Similarly any properties
  attached to messages are also dumped and restored. Any new
  information in the dump format is prefixed by '#' to allow existing
  scripts to ignore it.

Emacs
-----

Make notmuch-message-mode use insert for fcc

  Notmuch-message-mode now defaults to using notmuch insert for
  fcc. The old file based fcc behaviour can be restored by setting the
  defcustom `notmuch-maildir-use-notmuch-insert` to nil.

  When using notmuch insert, `notmuch-fcc-dirs` must be a subdirectory
  of the mailstore (absolute paths are not permitted) followed by any
  tag changes to be applied to the inserted message. The tag changes
  are applied after the default tagging for new messages. For example
  setting the header to "sentmail -inbox +sent" would insert the
  message in the subdirectory sentmail of the mailstore, add the tag
  "sent", and not add the (normally added) "inbox" tag.

  Finally, if the insert fails (e.g. if the database is locked) the
  user is presented with the option to retry, ignore, or edit the
  header.

Make internal address completion customizable

  There is a new defcustom `notmuch-address-internal-completion` which
  controls how the internal completion works: it allows the user to
  choose whether to match on messages the user sent, or the user
  received, and to filter the messages used for the match, for example
  by date.

Allow internal address completion on an individual basis

  There is a new function `notmuch-address-toggle-internal-completion`
  (by default it has no keybinding) which allows users who normally
  use an external completion command to use the builtin internal
  completion for the current buffer.

  Alternatively, if the user has company-mode enabled, then the user
  can use company mode commands such as `company-complete` to
  activate the builtin completion for an individual completion.

Resend messages

  The function `notmuch-show-resend-message` (bound to `b` in show
  and tree modes) will (attempt to) send current message to new
  recipients. The headers of the message won't be altered (e.g. `To:`
  may point to yourself). New `Resent-To:`, `Resent-From:` and so on
  will be added instead.

Face customization is easier

  New faces `notmuch-tag-unread`, `notmuch-tag-flagged`,
  `notmuch-tag-deleted`, `notmuch-tag-added`,
  `notmuch-search-flagged-face` and `notmuch-search-unread-face` are
  now used by default. Customize `notmuch-faces` to modify them.

Omit User-Agent header by default when sending mail

Ruby Bindings
-------------

Add support for `notmuch_database_get_all_tags`

Go Bindings
-----------

Go bindings moved to contrib

Add support for `notmuch_threads_t` and `notmuch_thread_t`

Fixed constant values so they are not all zero anymore

  Previously, it was impossible to open writable database handles,
  because `DATABASE_MODE_READ_ONLY` and `DATABASE_MODE_READ_WRITE` were
  both set to zero.
  The same issue occured with sort modes.


(wiz)