Update readme and examples

Addresses issue #290 by updating `README.md` and also by moving the Windows examples installation to where the `README.md` said they were (at the top level rather than under doc).

This also fixes #259 by preventing example binaries from being installed from a Debug build.

And I updated the version number examples in `README.md` to 3.5.

@mjhmilla and @chrisdembia, please review. Chris, I didn't try the installation on Linux to make sure I didn't mess up anything with the example installation (they should still go to the same place, but not for Debug builds). Also, it would be worth a quick check of the instructions for different platforms to see if they still match reality.
Very slightly unclear if you mean "Don't run on debug builds" or if you mean "doesn't exist on debug builds."