CHEF-4141 - FreeBSD support for ncurses build

Use gmake, not make
CHEF-4141 - FreeBSD support for libedit

Requires modifying vi.c in a similar manner as the patch found in the
FreeBSD ports tree.

See: /usr/ports/devel/libedit/files/patch-vi.c
CHEF-4141 - FreeBSD support for libiconv build

Use gmake, not make
CHEF-4141 - splat
CHEF-4141 - working, needs refactoring badly
CHEF-4141 - Cleanup merge artifacts and typos
don't hard-code commands to gmake

It's easier to just create a `make` symlink to `gmake` in the build 
slave. This also follows the same pattern we used for Solaris builds.
remove unused software definitions

`libffi` and `libexecinfo` are no longer needed for FreeBSD builds so 
we'll just remove them so they don't bit rot.
format/style changes
remove trailing whitespace