Fix `less` not auto-exiting on long lines.

I noticed that `less -FS` won't exit when encountering very long lines, even if output is shorter than screen height, which forces me to check if I need to press `q` after running `git r` and `git ra`.

I wrote `nowrap` function to always be sure that I can start typing next terminal command right away. It has an unfortunate side effect of altering very last character on the line, due to the nature of how it works, but other than that it seems to be working perfectly.

Tested only in iTerm and regular Terminal (zsh and bash) on OS X, but it should work in any vt100 emulating terminal, which is pretty much everything available today.

```
$ sw_vers
ProductName:    Mac OS X
ProductVersion: 10.9.2
BuildVersion:   13C64
$ cat ~/Applications/iTerm.app/Contents/Info.plist | egrep -A1 CFBundleVersion
        <key>CFBundleVersion</key>
        <string>1.0.0.20140421</string>
$ zsh --version
zsh 5.0.5 (x86_64-apple-darwin13.0.0)
$ bash --version
GNU bash, version 3.2.51(1)-release (x86_64-apple-darwin13)
Copyright (C) 2007 Free Software Foundation, Inc.
$ tmux -V
tmux 1.9a
```