This way we ensure that a block always have the external resources from its ancestors as this will be necessary most of the time. From now on, the JS widget of the blocks will inherit from a common ancestor to factorize some mechanisms that are duplicates at many levels.
This can be disabled in a particular block by overloading the INCLUDE_ANCESTORS_DEFAULT_XXX_FILES constants in which case, only the external files of the block itself will be included.
