This commit was supposed to be on a separate branch.

Revert "Proposing a directory structure.  Classes are there, but unimplemented (git cannot create empty folders)."

This reverts commit 9d6f88eb0f67194d3d55f3ddd686c5db44157138.
We are now willing to add directory structure.  The delete from the master branch has been rendered unnecessary.  Merge conflicts resolved by re-adding files.
Adding skeleton classes Tile Space HexTile and HexSpace as described in the UML.
Only interfacing has been described, no implementation was added.
adding method stubs to HexTile and HexSpace.  Still not implemented, but won't give compile errors.
Merge branch 'master' into CGI.