Getting Clojure installed and running and "G'day World"-ing

G'day:
This is just another one of those article about my experience with working out how to get a language operational in my dev environment. All it really serves to do is to demonstrate there's not much to it, so it should not be a "barrier to entry" if you decide to have a look at Clojure. I am way too much a newbie with it to be offering anything actually insightful here though.

Obviously that said if one's just wanting to give it a bash, there's online REPLs about the place (eg: Try Clojure) so no need to install it, but their scope will be limited, and for some reason I prefer to have stuff running locally.

I've worked through the Try Clojure tutorial before - ages ago - but other than that know nothing about it other than it seems to be overly in love with parentheses. Here goes...