Update launch script

Update launch script to:
- Store the pid of the "java -jar jetty-runner.jar [...]" process into a
server.pid file and the port used to deploy the application into a
server.port file.
- Detect if an instance of RUbioSeq-GUI is deployed (i.e. the pid stored
in the server.pid file corresponds to a process that is running).
- Detect if the port is un use. If the port is in use, the application
is not re-deployed and only the local browser is openned.
Add stop script

Add stop script to kill the process indicated in the server.pid file.