ITK/Release 4/Modularization/ Add a module

1. Choose a group for your module

 Add your module into  "ITK/CMake/ITKGroups.cmake" to be include in ITK.

2. Organize the source tree.

 Modules are located under "ITK/Modules/<Group>/".
 In each module, there are "include","src", "test" subdirectories, where the headers, source code and testing code are located, respectively.

 The CMake components that are in need for  "ITK-FOO" module in the Filtering group:
  * File:Modules/Filtering/Foo/CMakeLists.txt
  * File:Modules/Filtering/Foo/itk-module.cmake
  * File:Modules/Filtering/Foo/src/CMakeLists.txt 
  * File:Modules/Filtering/Foo/test/CMakeLists.txt 
 

An example: Add "ITK-FastMarching" module to ITK [1]