- In the parent pom.xml, change tomcat version

- In the parent pom.xml, add a new variable to store the major version of tomcat (for the download)
- In the parent pom.xml, add a new variable to store the valve version
- Modify the pom.xml of bundle/tomcat to use the new variable for the major version of tomcat
- Modify the pom.xml of deploy/distrib to use the new variable for the valve version
- Update the server.xml with the server.xml of tomcat 7