BUG: Update EMSegment to fix python module import on windows

This commit updates EMSegment to fix a regression introduced in
r25128 (STYLE: Simplify import of Logic/MRML/DisplayableManager
python modules).

It ensures python modules built on system (e.g Visual Studio) using
intermediate directories (e.g Release, Debug, ...) can be imported.

All EMSegment tests are now expected to pass on Windows.

From: Jean-Christophe Fillion-Robin <jchris.fillionr@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@25197 3bd1e089-480b-0410-8dfb-8563597acbee