Add Python 3.5.0rc1

https://www.python.org/downloads/release/python-350rc1/

plugins/python-build/share/python-build/3.5.0rc1

@@ -0,0 +1,3 @@
+#require_gcc
+install_package "readline-6.3" "http://ftpmirror.gnu.org/readline/readline-6.3.tar.gz#56ba6071b9462f980c5a72ab0023893b65ba6debb4eeb475d7a563dc65cafd43" standard --if has_broken_mac_readline
+install_package "Python-3.5.0rc1" "https://www.python.org/ftp/python/3.5.0/Python-3.5.0rc1.tgz#af300225b740401aaa3cb741568cd8a12fdb870b5f395ef8b1015dd45a6330bf" ldflags_dirs standard verify_py35 ensurepip