fix issues in PLCOpenEditor with moving from wxWidgets 2.8 to 3.0

1)
./PLCOpenEditor.py:63: wxPyDeprecationWarning: Using deprecated class PySimpleApp.
app = wx.PySimpleApp()

2)
./PLCOpenEditor.py:475: wxPyDeprecationWarning: Call to deprecated item.
wx.InitAllImageHandlers()

3)
Traceback (most recent call last):
File "./PLCOpenEditor.py", line 480, in <module>
frame = PLCOpenEditor(None, fileOpen=fileOpen)
File "./PLCOpenEditor.py", line 163, in __init__
IDEFrame.__init__(self, parent)
File "/tmp/f/beremiz/IDEFrame.py", line 657, in __init__
self._init_ctrls(parent)
File "/tmp/f/beremiz/IDEFrame.py", line 485, in _init_ctrls
self._init_icon(prnt)
File "/tmp/f/beremiz/IDEFrame.py", line 476, in _init_icon
if self.icon:
AttributeError: 'PLCOpenEditor' object has no attribute 'icon'

// import Nevow.Athena

function init() {
  Nevow.Athena.Widget.fromAthenaID(1).callRemote('HMIexec', 'HMIinitialisation');
}

WebInterface.PLC = Nevow.Athena.Widget.subclass('WebInterface.PLC');
WebInterface.PLC.method(
	 'updateHMI',
	 function (self, data) {
	   d = self.callRemote('getPLCElement');
	   d.addCallback(
			 function liveElementReceived(le) {
				d2 = self.addChildWidgetFromWidgetInfo(le);
				d2.addCallback(
						function childAdded(widget) {
						var node = self.nodeById('content');
						node.replaceChild(widget.node, node.getElementsByTagName('div')[0]);
						init();
						});
				});
	   });

Divmod.Base.addLoadEvent(init);