Use less(1) as default pager
rtld: Implement Interpose DSO flag

This implementation was sponsored by FreeBSD Foundation.

Taken from:
SVN 256101 (07 OCT 2013)
rtld: dl_iterate_phdr change

The dynamic linker needs to include itself when iterating over loaded
ELF objects in dl_iterate_phdr(3).

Taken by:
FreeBSD SVN 257811 (07 NOV 2013)
rtld: Add directory mapping functionality

Partially taken from:
FreeBSD SVN 255765 (21 SEP 2013)
libmap.conf: Update man page

Bring in DES' recent overhaul of the libmap.conf man page

Partially taken from:
FreeBSD SVN 255765 (21 SEP 2013)