use CustomIntCtrl instead of wx.SpinCtrl because it doesn't support
long integer needed for UDINT, (U)LINT types.

This commit complements commit 74a3f4d "fix LINT and ULINT ranges".

.. Beremiz documentation master file

Beremiz's documentation
=======================

Contents:

.. toctree::
   :maxdepth: 2

   overview
   manual/index
   standards