ext/pty/pty.c, ext/io/wait/wait.c, ext/openssl/ossl_ssl.c:
Use own buffering mechanism instead of stdio.
* io.c, ext/stringio/stringio.c, test/ruby/ut_eof.rb:
EOF flag removed.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@7473 b2dd03c8-39d4-4d8f-98ff-823fe69b080e