add submodules memtailor, mathic, and mathicgb

... and no longer consider them as libraries.  This commit is
incomplete and will not build.  The next thing to do is to
arrange for configuration and compilation to happen within the
submodules.
adding submodules, part 2
adding submodules, part 3
adding submodules, part 3
adding submodules, part 3
adding submodules, part 4