Implement crash handling on Linux

This will allow us to generate crash dumps and have users report
crashes.

MultiMC.cpp

@@ -327,8 +327,11 @@ void MultiMC::initLogger()
 	logger.addDestination(m_debugDestination.get());
 	// log all the things
 	logger.setLoggingLevel(QsLogging::TraceLevel);
+	loggerInitialized = true;
 }
 
+bool loggerInitialized = false;
+
 void MultiMC::initGlobalSettings()
 {
 	m_settings.reset(new INISettingsObject("multimc.cfg", this));