fix issue, then it wasn't possible to remove functional blocks from
project using right click and popup menu.

The problem is that, PopupMenu was called using IDEFrame object and as
a result item in ProjectTree loosed focus and focus went to IDEFrame.
Therefore later functions couldn't detect which item in ProjectTree
was selected.

     1

from py_ext import *

     2

from PythonEditor import PythonEditor

     3

from PythonFileCTNMixin import PythonFileCTNMixin