link Scala and sbt
rephrase a bit
link #rust IRC channel
update post 7 date, unset draft
simplify post, fix typos, rephrase

I cut out the paragraph about lifetimes and ownership. I'd like to write about
that some time, but I think it deserves its own post. Also, the attention span
of the average HN reader is probably shorter than /r/rust or /r/programming
readers, and the target audience of this post is somewhat broader than the other
posts.
add Robigo Luculenta picture
do not show the entire post on the front page
rephrase to make the post more fluent