feat: add local http server

Added the JADS (https://github.com/bocallaghan/JADS) Node.js http server script as a grunt task. Running 'grunt execute' now launches an express web http server to serve the generated app. The JADS server includes proxy capabilities. Goto localhost:8080 to run the generated app in the browser. The port can be configured in the JADS/config.js file.
fix: removed git sub module for JADS - files now tracked
fix(JADS): enable sapui5 alias in config.js