Change of component for YARP & ICUB subprojects in codyco-superbuild

[traversaro]

To better support between switching between master and devel branches, as explained in https://github.com/robotology/codyco-superbuild/blob/master/README.md#handling-the-devel-branch , we switched the YCM COMPONENT of the YARP and ICUB subprojects from external to libraries.

If you are downloading and compiling YARP and ICUB using the superbuild, this means (assuming that your build directory is called build) that now the repository will be downloaded in codyco-superbuild/libraries/YARP and codyco-superbuild/libraries/ICUB and the build folder will be found in codyco-superbuild/build/libraries/YARP and codyco-superbuild/build/libraries/ICUB.

To avoid confusion in the future and keep your system clean, it is recommended to delete the old directories:

codyco-superbuild/external/YARP
codyco-superbuild/external/ICUB
codyco-superbuild/build/external/YARP
codyco-superbuild/build/external/ICUB

cc @robotology/codyco-developers