Support tools and install scripts

These are various scripts which aid for installation on Raijin.

• nci_install is for the newer versions of Payu, which use a fixed Python executable and rely on entry points for command line execution.
• legacy_install is for older versions, which have less strict install requirements (mostly due to internal bootstrapping techniques which re-apply similar constraint)
• get-pip.py is a small script available publicly which install pip for Python 2.6.