Added stackless-3.3.7

plugins/python-build/share/python-build/stackless-3.3.7

@@ -0,0 +1,4 @@
+#require_gcc
+install_package "openssl-1.0.2k" "https://www.openssl.org/source/openssl-1.0.2k.tar.gz#6b3977c61f2aedf0f96367dcfb5c6e578cf37e7b8d913b4ecb6643c3cb88d8c0" mac_openssl --if has_broken_mac_openssl
+install_package "readline-6.3" "https://ftpmirror.gnu.org/readline/readline-6.3.tar.gz#56ba6071b9462f980c5a72ab0023893b65ba6debb4eeb475d7a563dc65cafd43" standard --if has_broken_mac_readline
+install_package "stackless-3.3.7-slp" "https://github.com/stackless-dev/stackless/archive/v3.3.7-slp.tar.gz#f05b8ff8a0e318aa5880dc995518ab4453894d068a26a171b89e21b98da5a5c1" ldflags_dirs standard verify_py33 ensurepip