Three miscellaneous improvements for Vim

@kballard 'textwidth' is just fine for this, and 79 is the correct value, not 80, for the reasons indicated in the issue given.

I do not see what the position in which it breaks thing has got to do with it. Sure, it may go wrapping your code in a way you don’t like if you’re not careful, but that will push you in the direction of fixing it up properly.

Personally I find the most useful thing about setting 'tw' is that you can use gq on comments.

I do not believe that 'colorcolumn' is an appropriate solution, for multiple reasons. (a) it is hated by some people as a real ugliness, especially in colorschemes that have not optimised it at all (we’d earn enemies by setting it, and there is no precedent for doing it ourselves that I know of), and (b) it’s only supported for Vim 7.3 and later. As it happens, I *do* have `ccu=+1,+21`, but I do not think it would be a good idea to put it here. But if we *did* set 'ccu', I would want 'tw' set too.