View source for 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:
   * [[ITK_Release_4/Modularization/Add a module/CMakeLists.txt |Modules/Filtering/Foo/CMakeLists.txt]]
   * [[ITK_Release_4/Modularization/Add a module/itk-module.cmake |Modules/Filtering/Foo/itk-module.cmake]]
   * [[ITK_Release_4/Modularization/Add a module/test/CMakeLists.txt|Modules/Filtering/Foo/test/CMakeLists.txt]] 
   * If this module generates a library or libraries (has .cxx source files): [[ITK_Release_4/Modularization/Add a module/src/CMakeLists.txt|Modules/Filtering/Foo/src/CMakeLists.txt]]


Examples: 
* All modules in ITK.
* Adding a moule is easy. Arnaud did it without intructions: added "ITK-FastMarching" module to ITK (No libraries. Templated source code only.) [http://review.source.kitware.com/#change,1311].