Currently the fs related subsystem is broken in trunk, because of

Currently the fs related subsystem is broken in trunk, because of
linking problems. This patch:
 - Add the files fs/Module.cc,h which are similar to esi/Module.* files
 - Build a new library libfs.a
 - The  fs/aufs/StoreFSaufs.cc, fs/diskd/StoreFSdiskd.cc and
   fs/ufs/StoreFSufs.cc now contain just fake pointers
 - The FS::Init() method used to build  ufs, aufs and diskd filesystems.
 - The FS::Init method called in main.cc before the code which reads the
   config files. The FS::clean() currently does not used.
 - The coss file system initiated using the old way.