(QENG-989,990) Clean up open source install rough edges

This ensures that puppet and friends are available after gem installs on
Solaris and Debian. It also makes sure that the config directory and
hiera.yaml file are aways present. The former change fixes QENG-989 while
the latter fixes QENG-990).
I am not familiar enough with gems to know the difference between `/var/lib/gems/1.8/bin` and `/var/lib/gems/bin`, but it seems to me like this is prescribing a particular ruby or gem version. Is it safe to always assume 1.8 here?