Add pre-install chef packages script

Packages are already installed on image snapshot u1204-130529-gvc
(38b0b5a5-7dda-4fd1-b53a-00ba47eacc16). This decreases the time to
setup chefserver

Change-Id: I48022ce1a66f6730681ee403feaab9d00915a45f
Fix that chefserver scripts are hardcoded twice

The two are merged into one

Change-Id: I0faca4b7357baeacacf5e6fbddccad75b339e7d3