BUG: Fix CMake 3.x configuration warnings

Test done using CMake 3.0.20140413 (g94d5a)

Since project version is explicitly set, avoid warning by setting
policy CMP0048

Since ITKConfig.cmake append value to "ITK_LIBRARIES" and "ITK_INCLUDE_DIRS"
variables, let's make sure that "ITKFactoryRegistration" is not in the list
when configuring "ITKFactoryRegistration". This fixes the following
warnings:

//--------------
CMake Warning (dev) at Libs/ITKFactoryRegistration/CMakeLists.txt:55 (add_library):
Policy CMP0038 is not set: Targets may not link directly to themselves.
Run "cmake --help-policy CMP0038" for policy details. Use the cmake_policy
command to set the policy and suppress this warning.

Target "ITKFactoryRegistration" links to itself.
This warning is for project developers. Use -Wno-dev to suppress it.
//--------------

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23099 3bd1e089-480b-0410-8dfb-8563597acbee