Merge upstream/master into merge/upstream-full

Merge profanity-im/profanity master (373 commits) into cproof fork.

Source changes (manual merge):
- src/command/: cmd_defs, cmd_funcs, cmd_ac — upstream g_new0, auto_gchar,
  launch_editor callback; keep our XEP-0308 LMC, force-encryption, CWE-134
- src/config/: preferences, tlscerts, account — upstream UNIQUE dedup,
  dynamic pad capacity; keep our db_history_result_t, scroll logic
- src/database.*: upstream g_new0 memory mgmt; keep our return types,
  add null-check fix for msg->timestamp
- src/omemo/, src/pgp/: upstream _gpgme_key_get_email, g_new0;
  keep our replace_id in omemo_on_message_send
- src/tools/: editor, http_upload, bookmark_ignore — upstream launch_editor
  callback API
- src/ui/: console, window, chatwin, mucwin, inputwin, buffer —
  upstream win_warn_needed/sent dedup, PAD_MIN_HEIGHT dynamic pads;
  keep our y_start_pos scroll, _truncate_datetime_suffix
- src/xmpp/: message, stanza, presence, roster_list, iq, session —
  upstream connection_get_available_resources; keep our LMC stanza logic
- src/common.c: fix format-security (cons_show)

Build system:
- Makefile.am: updated test paths to subdirectory structure, added
  test_cmd_ac, test_forced_encryption
- Restored autotools files deleted by upstream meson migration:
  bootstrap.sh, autogen.sh, m4/ax_valgrind_check.m4, configure-debug

Tests:
- Unit tests: upstream unittests.c base + our forced_encryption tests
  (482 passed, 0 failed across all 4 configurations)
- Functional tests: kept our version (93 passed, 0 failed)
  upstream version requires stbbr_for_xmlns not yet in our stabber fork
- Updated test stubs: stub_xmpp.c, stub_omemo.c from upstream

Compile fixes:
- src/common.c: cons_show(errmsg) -> cons_show("%s", errmsg)
- src/database.c: null-check before msg->timestamp access
- src/ui/console.c: size_t -> (int) cast for format width
- src/config/tlscerts.c: %d -> %zu for size_t

tests/unittests/log/stub_log.c

@@ -3,21 +3,7 @@
  *
  * Copyright (C) 2012 - 2019 James Booth <boothj5@gmail.com>
  *
- * This file is part of Profanity.
- *
- * Profanity is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Profanity is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Profanity.  If not, see <http://www.gnu.org/licenses/>.
- *
+ * SPDX-License-Identifier: GPL-3.0-or-later WITH OpenSSL-exception
  */
 
 #include <glib.h>
@@ -60,10 +46,10 @@ log_msg(log_level_t level, const char* const area, const char* const msg)
 {
 }
 
-const char*
+const gchar*
 get_log_file_location(void)
 {
-    return mock_ptr_type(char*);
+    return mock_ptr_type(gchar*);
 }
 
 int