Use -r with less for help output

On some platforms, such as Fedora, groff by default outputs control
characters which less will display escaped by default (on other
platforms such as Debian and OSX this is disabled via local
customisations and falls back to the old method of backspacing over
characters).

Using less -R as the pager means that output looks correct in both
cases.
Merge branch 'ianw-help-ascii' into develop

* ianw-help-ascii:
  Use -r with less for help output