Add specific platform encoding functions for FreeBSD, OpenBSD and NetBSD

Supports ASCII, UTF-8 and Latin-1 locales;
Uses slightly adjusted version of the linux-specific encoding functions

Signed-off-by: Reini Urban <rurban@cpanel.net>
[cage] Fixup BSD encodings with UTF8, build-system integration

ChangeLog, MANIFEST, Makefile, Copyright dates.
Closes pull request #1092
Merge branch 'smoke-me/bsd-encodings-gh1092'

Smoked fine