Try to be systematic about dealing with socket and ssl exceptions in
FakeSocket.makefile().  The previous version of the code caught all
ssl errors and treated them as EOF, even though most of the errors
don't mean EOF.

An SSL error can mean on of three things:

    1. The SSL/TLS connection was closed.
    2. The operation should be retried.
    3. An error occurred.

Also, if a socket error occurred and the error was EINTR, retry the
call.  Otherwise, it was a legitimate error and the caller should
receive the exception.