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'

     1

<?xml version='1.0' encoding='utf-8'?>

     2

<BeremizRoot xmlns:xsd="http://www.w3.org/2001/XMLSchema">

     3

  <TargetType>

     4

    <Generic Command="make -C %(buildpath)s -f ../project_files/Makefile all BEREMIZSRC=%(src)s BEREMIZCFLAGS=%(cflags)s MD5=%(md5)s USE_BEREMIZ=1 FROM_BEREMIZ=1"/>

     5

  </TargetType>

     6

  <Libraries Enable_Native_Library="false" Enable_Python_Library="false" Enable_SVGUI_Library="false"/>

     7

</BeremizRoot>