Merge Python 3 porting.

diff --cc src/PYLIGHTGUI/PYLIGHTGUI.py
index 03e8dbd5d94f8899300a6ff1b4bf0fcf3c52bdbb,3fabc1d504fa53bf2c3926b3de273467c0ba924f..54e5744512e4c1d4f4c54afcade3efd1a6ee0f4a
--- 1/src/PYLIGHTGUI/PYLIGHTGUI.py
--- 2/src/PYLIGHTGUI/PYLIGHTGUI.py
+++ b/src/PYLIGHTGUI/PYLIGHTGUI.py
@@@ -130,13 -154,20 +130,13 @@@ def initialize()
  # called when module is activated
  # returns True if activating is successfull and False otherwise
  def activate():
-     if verbose() : print "PYLIGHTGUI.activate()"
 -    if verbose() : print("PYLIGHTGUI.activate() : study : %d" % _getStudyId())
 -    ctx = _setContext( _getStudyId() )
++    if verbose() : print("PYLIGHTGUI.activate()")
 +    GUIcontext()
      return True
  
  # called when module is deactivated
  def deactivate():
-     if verbose() : print "PYLIGHTGUI.deactivate()"
 -    if verbose() : print("PYLIGHTGUI.deactivate() : study : %d" % _getStudyId())
 -    pass
 -
 -# called when active study is changed
 -# active study ID is passed as parameter
 -def activeStudyChanged( studyID ):
 -    if verbose() : print("PYLIGHTGUI.activeStudyChanged(): study : %d" % studyID)
 -    ctx = _setContext( _getStudyId() )
++    if verbose() : print("PYLIGHTGUI.deactivate()")
      pass
  
  # Process GUI action
@@@ -153,8 -184,7 +153,8 @@@ def OnGUIEvent(commandID)
  
  # Customize popup menu
  def createPopupMenu(popup, context):
-     if verbose() : print "PYLIGHTGUI.createPopupMenu(): context = %s" % context
 +    global __data_model__
+     if verbose() : print("PYLIGHTGUI.createPopupMenu(): context = %s" % context)
  
      if context != 'ObjectBrowser':
          return
@@@ -187,20 -219,20 +187,20 @@@
  
  # For saving data in the study
  def saveFiles(prefix):
-     if verbose(): print "PYLIGHTGUI::saveFile()"
 +    global __data_model__
 -    ctx = _setContext( _getStudyId() )
+     if verbose(): print("PYLIGHTGUI::saveFile()")
      postfix = "PYLIGHT.txt"
      filename = prefix+postfix
 -    ctx.DM.saveFile(filename)
 +    __data_model__.saveFile(filename)
      return postfix
  
  # For restore data from the study
  def openFiles(filelist):
-     if verbose(): print "PYLIGHTGUI::openFile()"
 +    global __data_model__
 -    ctx = _setContext( _getStudyId() )
+     if verbose(): print("PYLIGHTGUI::openFile()")
      filename =  filelist[0]
      filename.append(filelist[1])
 -    ctx.DM.loadFile(filename)
 +    __data_model__.loadFile(filename)
      return True
  
  # Loading a text file
@@@ -313,11 -341,11 +309,11 @@@ def insertLine()
          
  # Edit selected line
  def editLine():
 -    ctx = _setContext( _getStudyId() )
 +    global __data_model__
      if sg.SelectedCount() == 1:
          entry = sg.getSelected( 0 )
 -        obj = ctx.DM.getObject(entry)
 +        obj = __data_model__.getObject(entry)
-         if(obj.getText() != "\n"):
+         if(obj is not None and obj.getText() != "\n"):
              #Get text line
              res = QInputDialog.getText(sgPyQt.getDesktop(),
                                         "Edit line",
@@@ -349,7 -377,10 +345,10 @@@ def removeLine()
      while selcount != 0:
          entry = sg.getSelected( selcount - 1)
          #Check what only lines selected
-         if __data_model__.getObject(entry).getText() == "\n":
 -        obj = ctx.DM.getObject(entry)
++        obj = __data_model__.getObject(entry)
+         if obj is None:
+             continue
+         if obj.getText() == "\n":
              onlyLines = False
              break
          lines.append(entry)
@@@ -427,7 -464,13 +432,13 @@@ def eraseLine()
      if sg.SelectedCount() != 1:
          return
      entry = sg.getSelected(0)
-     text = __data_model__.getObject(entry).getText()
 -    obj = ctx.DM.getObject(entry)
++    obj = __data_model__.getObject(entry)
+     if obj is None:
+         QMessageBox.information(sgPyQt.getDesktop(),
+                                 'Info',
+                                 'Please, select line!')
+         return
+     text = obj.getText()
      if text == "\n":
          return
      renderer=libSalomePy.getRenderer()