ENH: Add module vtkInteractionStyle when needed.

If vtkRenderWindowInteractor is used then there is a
 dependency on vtkInteractionStyle.

Thanks to Bill Lorenson for finding this when testing
 http://review.source.kitware.com/#/c/13252/

Change-Id: I7f12d8948822c0b92b6a3237e63f9e674548246d
Signed-off-by: Andrew Maclean <andrew.amaclean@gmail.com>
Allow the examples to specify what modules to use.

This approach demonstrates good programming practice by only
linking to the needed modules.
It also removed the need to set CMP0020 to NEW in all cases
except those examples that link to Qt.

The include(${VTK_USE_FILE}) has been removed from the
top-level CMakeLists.txt file as it is unnecessary.

The solution presented here will work with the Examples built
as a stand-alone folder or within the VTK tree or with the
individual examples.

They have been tested on Linux, Windows VS2012 Express,
Mac OS-X 10.9 using Qt5.1.1.

Change-Id: I0572a395b2ebc6630db8c1407f410a584f668a85
Signed-off-by: Andrew Maclean <andrew.amaclean@gmail.com>
Removed unused typedef

Fixes gcc -Wunused-local-typedefs warning, which is
part of -Wall in gcc 4.8.

Change-Id: I644d57eaa43e6321497ac0948aad6a033dca4b94
Merge topic 'WhatModulesVTK-add-vtkInteractionStyle' into master

5eed982e ENH: Add module vtkInteractionStyle when needed.
Merge topic 'make-vtk-examples-build' into master

733ef2dd Allow the examples to specify what modules to use.
Merge topic 'Wunused-local-typedefs-fix' into master

5a92d059 Removed unused typedef