Enable all scripts to be run silently

[dhruvkb]

The scripts for cloning and building all ask questions to tune and tweak the build process. There should also be an option to be able to provide these answers as arguments or as environment variables during script invocation so that the process may be completed silently and without monitoring from the user.

This would also allow us to develop end-to-end scripts that complete the entire process from clone to deployment without supervision.