Remove superfluous error messages and handle uncaught exceptions

Spectrum2/backend.py

@@ -262,7 +262,6 @@ class SpectrumBackend:
 
 	def handleConvMessagePayload(self, data):
 		payload = protocol_pb2.ConversationMessage()
-		self.logger.error("handleConvMessagePayload")
 		if (payload.ParseFromString(data) == False):
 			#TODO: ERROR
 			return

session.py

@@ -437,6 +437,8 @@ class Session(YowsupApp):
 		try:
 			buddy = self.buddies[buddy]
 		except KeyError:
+			# Sometimes whatsapp send our own presence
+			if buddy != self.legacyName:
 				self.logger.error("Buddy not found: %s", buddy)
 			return
 

transwhat.py

@@ -62,7 +62,13 @@ logging.basicConfig( \
 
 # Handler
 def handleTransportData(data):
+	try:
 		plugin.handleDataRead(data)
+	except SystemExit as e:
+		raise e
+	except:
+		logger = logging.getLogger('transwhat')
+		logger.error(traceback.format_exc())
 
 e4u.load()