Upgrade of installation scripts for Ubuntu 14.04 (trusty)

- Upgraded installation scripts  for Ubuntu 14.04 (trusty).
- Reorganized and improved install/config scripts.
      - There is a config file for the settings, which reduces interactivity during installation.
      - Any git branch can be used for installation.
      - There is no need to push to github before some local changes can be tested.
- etc.