title: Qthread is still working when i close gui on python pyqt
body: <p>my code has thread, but when i close the gui, it still works on background. how can i stop threads? is there something stop(), close()?
  i dont use signal, slots? Must i use this?</p>
  
  <pre><code>from PyQt4 import QtGui, QtCore
  import sys
  import time
  import threading
  
  class Main(QtGui.QMainWindow):
      def __init__(self, parent=None):
          super(Main, self).__init__(parent)
          self.kac_ders=QtGui.QComboBox()
          self.bilgi_cek=QtGui.QPushButton("Save")
          self.text=QtGui.QLineEdit()
          self.widgetlayout=QtGui.QFormLayout()
          self.widgetlar=QtGui.QWidget()
          self.widgetlar.setLayout(self.widgetlayout)
          self.bilgiler=QtGui.QTextBrowser()
          self.bilgi_cek.clicked.connect(self.on_testLoop)
          self.scrollArea = QtGui.QScrollArea()
          self.scrollArea.setWidgetResizable(True)
          self.scrollArea.setWidget(self.widgetlar)
          self.analayout=QtGui.QVBoxLayout()
          self.analayout.addWidget(self.text)
          self.analayout.addWidget(self.bilgi_cek)
          self.analayout.addWidget(self.bilgiler)
          self.centralWidget=QtGui.QWidget()
          self.centralWidget.setLayout(self.analayout)
          self.setCentralWidget(self.centralWidget)
  
      def on_testLoop(self):
          self.c_thread=threading.Thread(target=self.kontenjan_ara)
          self.c_thread.start()
  
      def kontenjan_ara(self):
  
          while(1):
                  self.bilgiler.append(self.text.text())
                  time.sleep(10)
  
  
  app = QtGui.QApplication(sys.argv)
  myWidget = Main()
  myWidget.show()
  app.exec_()
  </code></pre>