Add proper less to image (disable busybox less)

The version of less in busybox is quite annoying when working on OpenELEC. It doesn't properly support searching in files or tailing (and interrupting) logfiles. It also doesn't properly handle non-ascii characters. This patch disables busybox less and instead adds the latest stable less release.
Merge pull request #2209 from dagwieers/package-less

Replace busybox less with *real* less