Add `less` wrapper function
Add `less` wrapper function

I asked this question here:

http://superuser.com/questions/992743/make-less-use-alternate-screen-but-only-if-entire-file-wont-fit-on-one-screen/

But later found this:

https://github.com/johnmellor/scripts/blob/a8788bf50ec1d/bin/least

This works pretty nicely, although I've made something simpler (and less
flexible) here.

Of course, I then realized that it doesn't work as a pager for `git` et
al because it is a function, and what those need is an executable.
Unfortunately, to avoid hard-coding an absolute path to the real `less`
executable, any such wrapper executable I might make needs to be named
something other than `less`... So, I'll move this and name it
appropriately in another commit.

wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent