make mki18n.py wx-3.0 compatible and fix segmentation fault

$ python mki18n.py -m -v --moTarget=../locale --domain=Beremiz
No project directory given. Using current one: /home/beremiz/beremiz/i18n
Application domain used is: 'Beremiz'
Target directory for .mo files is: ../locale
../src/common/stdpbase.cpp(62): assert "traits" failed in Get(): create wxApp before calling this
Segmentation fault

from py_ext import *
from PythonEditor import PythonEditor
from PythonFileCTNMixin import PythonFileCTNMixin