Move Qt 5 version to 5.15.3 open source.

- Show viewers count in RTMP streams.
- Send GIFs search results without "via @bot".
- Display the file thumbnail in downloads bar.
- Always try to save original photo bytes to disk.
- Fix crash when deleting a user from your contacts list.

.gitmodules

@@ -52,9 +52,6 @@
 [submodule "Telegram/lib_qr"]
 	path = Telegram/lib_qr
 	url = https://github.com/desktop-app/lib_qr.git
-[submodule "Telegram/ThirdParty/libdbusmenu-qt"]
-	path = Telegram/ThirdParty/libdbusmenu-qt
-	url = https://github.com/desktop-app/libdbusmenu-qt.git
 [submodule "Telegram/ThirdParty/hunspell"]
 	path = Telegram/ThirdParty/hunspell
 	url = https://github.com/hunspell/hunspell

Telegram/CMakeLists.txt

@@ -147,6 +147,8 @@ PRIVATE
     api/api_text_entities.h
     api/api_toggling_media.cpp
     api/api_toggling_media.h
+    api/api_unread_things.cpp
+    api/api_unread_things.h
     api/api_updates.cpp
     api/api_updates.h
     api/api_user_privacy.cpp
@@ -278,6 +280,8 @@ PRIVATE
     calls/group/calls_group_menu.h
     calls/group/calls_group_panel.cpp
     calls/group/calls_group_panel.h
+    calls/group/calls_group_rtmp.cpp
+    calls/group/calls_group_rtmp.h
     calls/group/calls_group_settings.cpp
     calls/group/calls_group_settings.h
     calls/group/calls_group_toasts.cpp
@@ -422,6 +426,8 @@ PRIVATE
     data/data_document_media.h
     data/data_document_resolver.cpp
     data/data_document_resolver.h
+    data/data_download_manager.cpp
+    data/data_download_manager.h
     data/data_drafts.cpp
     data/data_drafts.h
     data/data_folder.cpp
@@ -686,6 +692,8 @@ PRIVATE
     history/history_message.h
     history/history_service.cpp
     history/history_service.h
+    history/history_unread_things.cpp
+    history/history_unread_things.h
     history/history_widget.cpp
     history/history_widget.h
     info/info_content_widget.cpp
@@ -706,13 +714,25 @@ PRIVATE
     info/common_groups/info_common_groups_inner_widget.h
     info/common_groups/info_common_groups_widget.cpp
     info/common_groups/info_common_groups_widget.h
+    info/downloads/info_downloads_inner_widget.cpp
+    info/downloads/info_downloads_inner_widget.h
+    info/downloads/info_downloads_provider.cpp
+    info/downloads/info_downloads_provider.h
+    info/downloads/info_downloads_widget.cpp
+    info/downloads/info_downloads_widget.h
     info/media/info_media_buttons.h
+    info/media/info_media_common.cpp
+    info/media/info_media_common.h
     info/media/info_media_empty_widget.cpp
     info/media/info_media_empty_widget.h
     info/media/info_media_inner_widget.cpp
     info/media/info_media_inner_widget.h
+    info/media/info_media_list_section.cpp
+    info/media/info_media_list_section.h
     info/media/info_media_list_widget.cpp
     info/media/info_media_list_widget.h
+    info/media/info_media_provider.cpp
+    info/media/info_media_provider.h
     info/media/info_media_widget.cpp
     info/media/info_media_widget.h
     info/members/info_members_widget.cpp
@@ -1027,6 +1047,8 @@ PRIVATE
     settings/settings_codes.h
     settings/settings_common.cpp
     settings/settings_common.h
+    settings/settings_experimental.cpp
+    settings/settings_experimental.h
     settings/settings_folders.cpp
     settings/settings_folders.h
     settings/settings_information.cpp
@@ -1091,6 +1113,8 @@ PRIVATE
     support/support_common.h
     support/support_helper.cpp
     support/support_helper.h
+    support/support_preload.cpp
+    support/support_preload.h
     support/support_templates.cpp
     support/support_templates.h
     ui/chat/attach/attach_item_single_file_preview.cpp
@@ -1103,6 +1127,9 @@ PRIVATE
     ui/chat/choose_theme_controller.h
     ui/effects/fireworks_animation.cpp
     ui/effects/fireworks_animation.h
+    ui/effects/message_sending_animation_common.h
+    ui/effects/message_sending_animation_controller.cpp
+    ui/effects/message_sending_animation_controller.h
     ui/effects/round_checkbox.cpp
     ui/effects/round_checkbox.h
     ui/effects/send_action_animations.cpp
@@ -1163,8 +1190,6 @@ PRIVATE
     window/window_main_menu.h
     window/window_media_preview.cpp
     window/window_media_preview.h
-    window/window_outdated_bar.cpp
-    window/window_outdated_bar.h
     window/window_peer_menu.cpp
     window/window_peer_menu.h
     window/window_section_common.h
@@ -1193,8 +1218,6 @@ PRIVATE
     window/themes/window_themes_generate_name.h
     apiwrap.cpp
     apiwrap.h
-    app.cpp
-    app.h
     config.h
     facades.cpp
     facades.h
@@ -1334,8 +1357,6 @@ else()
     if (NOT DESKTOP_APP_DISABLE_DBUS_INTEGRATION)
         target_link_libraries(Telegram
         PRIVATE
-            desktop-app::external_statusnotifieritem
-            desktop-app::external_dbusmenu_qt
             desktop-app::external_glibmm
             desktop-app::external_glib
         )