update for rename of exercises/assignment5.mdwn to exercises/assignment5-6.mdwn
rename exercises/assignment6-7.mdwn to exercises/assignment7.mdwn
rename exercises/assignment7.mdwn to exercises/assignment6-7.mdwn
add parentheses
fix link
update for rename of topics/closures.mdwn to topics/week7__95__environments__95__and__95__closures.mdwn
extract closures discussion to separate page
add more bold
add toc
tweak
add explanation of Closures
markup
use arrow for mid
More explicitness
formatting
tweaks
update homework
tweaks
argh... Haskell vs OCaml
fix formatting of `1`