[plt-dev] racket & gracket now the main executables

If you build your own installation, `make' now creates binaries named
`racket' and `gracket' instead of `mzscheme' and `mred'. When you
install, `mzscheme' and `mred' executables are created.

If you build over an existing installation, you may have to clear out
your "plt/bin" directory and/or remove ".app" or ".exe" files before
installing, because `rico setup' assumes that existing executables are
correct. (That's not a change; `setup-plt' has made the same assumption
many years.)

If you build with shared libraries (which is always the case under Mac
OS X and Windows), the names of the libraries have changed. I doubt
that we need compatibility libraries for Windows or Mac OS X, but for
Unix-style builds, it may make sense to provide soft-links from the old
names to the new ones.

Let me know if there are problems. I've tried a few builds on a few
platforms, but that leaves lots of room for error.