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:
  * Modules/Filtering/Foo/CMakeLists.txt
  * Modules/Filtering/Foo/itk-module.cmake
  * Modules/Filtering/Foo/test/CMakeLists.txt 
  * If this module generates a library or libraries (has .cxx source files): 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.) [1].