Merge branch 'master' into merge/upstream-full

Resolve conflicts after master gained the flat-file database backend,
AI client, and other cproof-fork features:

- CHANGELOG: keep cproof-fork unreleased section atop full upstream
  history (0.17.0 / 0.16.0 / 0.15.1)
- src/command/cmd_ac.c: keep both upstream spellcheck AC and cproof
  /history switch|verify|export|import autocompletion
- src/config/preferences.c: merge upstream [spellcheck] group with the
  cproof [ai]/[ai/<provider>] groups
- src/database.c: take master (thin dispatcher); upstream SQLite
  improvements (v3 migration, auto_gchar) belong in database_sqlite.c
  and will land in a follow-up commit
- src/tools/autocomplete.c: take upstream unescape of search_str
- src/ui/statusbar.c: keep guint signatures (per project preference)
  and adapt _status_bar_draw_dbbackend to guint as well
- src/xmpp/jid.c: combine the new jid_is_valid/jid_is_valid_user_jid
  with the "(null)" legacy-placeholder guard in
  jid_create_from_bare_and_resource; use auto_gchar
- tests/functionaltests/proftest.c: keep unsigned-safe pre-check on
  output_len before subtracting OUTPUT_BUF_SIZE
- tests/unittests/unittests.c: keep upstream subdirectory include
  layout plus cproof-only test_ai_client/database_export/database_stress
- tests/unittests/test_jid.c: drop orphan top-level copy (the
  restructured version lives in tests/unittests/xmpp/test_jid.c)

Upstream is included up to 1ac05754b (release 0.18.0 era). Follow-up:
pull 1ac05754b..upstream/master (esp. 42a849d16 db migration fix and
4749645c7 receipt-request restore), and adapt the SQLite improvements
into database_sqlite.c.

src/ui/console.c

@@ -1848,6 +1848,12 @@ cons_statusbar_setting(void)
         cons_show("Show tab with no actions (/statusbar)       : OFF");
     }
 
+    if (prefs_get_boolean(PREF_STATUSBAR_SHOW_DBBACKEND)) {
+        cons_show("Show database backend (/statusbar)          : ON");
+    } else {
+        cons_show("Show database backend (/statusbar)          : OFF");
+    }
+
     cons_show("Max tabs (/statusbar)                       : %d", prefs_get_statusbartabs());
 
     gint pref_len = prefs_get_statusbartablen();
@@ -1906,27 +1912,12 @@ cons_log_setting(void)
     cons_show("Log level (/log level)      : %s", level);
 }
 
-void
-cons_logging_setting(void)
-{
-    if (prefs_get_boolean(PREF_CHLOG))
-        cons_show("Chat logging (/logging chat)                : ON");
-    else
-        cons_show("Chat logging (/logging chat)                : OFF");
-
-    if (prefs_get_boolean(PREF_GRLOG))
-        cons_show("Groupchat logging (/logging group)          : ON");
-    else
-        cons_show("Groupchat logging (/logging group)          : OFF");
-}
-
 void
 cons_show_log_prefs(void)
 {
     cons_show("Logging preferences:");
     cons_show("");
     cons_log_setting();
-    cons_logging_setting();
 
     cons_alert(NULL);
 }
@@ -2809,11 +2800,6 @@ cons_privacy_setting(void)
     auto_gchar gchar* dblog = prefs_get_string(PREF_DBLOG);
     cons_show("Database logging                                           : %s", dblog);
 
-    if (prefs_get_boolean(PREF_CHLOG)) {
-        cons_show("Chat logging (/logging chat)                               : ON");
-    } else {
-        cons_show("Chat logging (/logging chat)                               : OFF");
-    }
     if (prefs_get_boolean(PREF_HISTORY)) {
         cons_show("Chat history (/history)                                    : ON");
     } else {