Use upstart to run hhvm-fastcgi service

Gives automatic restarts if the process dies

Also removes the need to install hhvm-fastcgi package, so
installing hhvm-nightly instead. Configuration migrated to ini
files (from hdf) and added to puppet as well.

Change-Id: Ia2faed1b4964a288c390a39d149ed3f86056544e
Merge "Use upstart to run hhvm-fastcgi service"