Update columncolor and reform lines with length>72

colorcolumn option changed to insert the column at 72, and all lines
that are of length greater than 72 were changed to split to a new line.

Given my setting of nuw=6, the colorcolumn will now appear at the very
edge of my terminal window, allowing me to see the entire contents of
the file without having to scroll horizontally, which for me is rather
convenient, as I am lazy and scrolling requires effort.