Merge PR from @chrros95

Several Changes:
- Uwsgi now listens on two sockets 8080 for http protocol and 8000 for uwsgi protocol
- Add a read_timeout in documentation for Nginx configuration 
- Expose 8024 properly in Core image
- Expose 8080 and 8000 both in Web image
- Rearange the commands to get even less number of layers.
- Add SIGINT as stop signal in web because uwsgi needs it shut down gracefully
- Enable threads in default uwsgi configuration

Fix #64, Fix #15

README.md

@@ -309,7 +309,7 @@ server {
                 # First attempt to serve request as file, then
                 include uwsgi_params;
                 uwsgi_pass 172.19.199.3:8000;
-
+                uwsgi_read_timeout 300;
         }
 
 }
@@ -369,4 +369,4 @@ more details.
 [11]: https://mailman.readthedocs.io/en/latest/src/mailman/docs/database.html
 [12]: http://www.postfix.org/
 [13]: http://semver.org/
-[14]: https://docs.docker.com/engine/security/trust/content_trust/
+[14]: https://docs.docker.com/engine/security/trust/content_trust/