Move some code around.

Move logs:SignalHandlers to core/crash_reports:CrashReports.
Move all pre-launch windows to core/crash_report_window module.
Move some global code to core/launcher:Launcher.
It should replace settings / platform_specific module in some way.

Telegram/SourceFiles/core/launcher.cpp

@@ -0,0 +1,106 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop version of Telegram messaging app, see https://telegram.org
+
+Telegram Desktop 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.
+
+It 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.
+
+In addition, as a special exception, the copyright holders give permission
+to link the code of portions of this program with the OpenSSL library.
+
+Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
+Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
+*/
+#include "core/launcher.h"
+
+#include "platform/platform_launcher.h"
+#include "platform/platform_specific.h"
+#include "core/crash_reports.h"
+#include "application.h"
+
+namespace Core {
+namespace {
+
+QStringList ReadArguments(int argc, char *argv[]) {
+	auto result = QStringList();
+	result.reserve(argc);
+	for (auto i = 0; i != argc; ++i) {
+		result.push_back(fromUtf8Safe(argv[i]));
+	}
+	return result;
+}
+
+} // namespace
+
+std::unique_ptr<Launcher> Launcher::Create(int argc, char *argv[]) {
+	return std::make_unique<Platform::Launcher>(argc, argv);
+}
+
+Launcher::Launcher(int argc, char *argv[])
+: _argc(argc)
+, _argv(argv)
+, _arguments(ReadArguments(argc, argv)) {
+	InitFromCommandLine(argc, argv);
+}
+
+void Launcher::init() {
+	QCoreApplication::setApplicationName(qsl("TelegramDesktop"));
+
+#ifndef OS_MAC_OLD
+	QCoreApplication::setAttribute(Qt::AA_DisableHighDpiScaling, true);
+#endif // OS_MAC_OLD
+
+	initHook();
+}
+
+int Launcher::exec() {
+	init();
+
+	if (cLaunchMode() == LaunchModeFixPrevious) {
+		return psFixPrevious();
+	} else if (cLaunchMode() == LaunchModeCleanup) {
+		return psCleanup();
+	}
+
+	// both are finished in Application::closeApplication
+	Logs::start(this); // must be started before Platform is started
+	Platform::start(); // must be started before QApplication is created
+
+	auto result = 0;
+	{
+		Application app(this, _argc, _argv);
+		result = app.exec();
+	}
+
+	DEBUG_LOG(("Telegram finished, result: %1").arg(result));
+
+#ifndef TDESKTOP_DISABLE_AUTOUPDATE
+	if (cRestartingUpdate()) {
+		DEBUG_LOG(("Application Info: executing updater to install update..."));
+		psExecUpdater();
+	} else
+#endif // !TDESKTOP_DISABLE_AUTOUPDATE
+	if (cRestarting()) {
+		DEBUG_LOG(("Application Info: executing Telegram, because of restart..."));
+		psExecTelegram();
+	}
+
+	CrashReports::Finish();
+	Platform::finish();
+	Logs::finish();
+
+	return result;
+}
+
+QString Launcher::argumentsString() const {
+	return _arguments.join(' ');
+}
+
+} // namespace Core