proxying to grunt config, set start_tomcat to executable

- http proxying through grunt:serve (https://www.npmjs.org/package/grunt-connect-proxy)
- mod executable on start_tomcat

Wie funktionierts:
1. npm install
2. start_tomcat.sh
3. grunt serve
4. im Browser eingeben: http://127.0.0.1:9000/conferencebuddy-web/user/
=> Resultat: Tomcat 405 im Browser bzw. "estaExceptionMessage: HTTP 405 Method Not Allowed" im Tomcat Log.