Improve NetBSD support

- add NetBSD Network support to the FreeBSD/Darwin support
- Fix the Makefile so "gmake tests" can work on NetBSD
- Add a basic implementation of NetBSDHardware to retrieve some hardware facts.
- set "ansible_architecture" in a way that makes more sense when machine name and processor name are different.

Tested on NetBSD 5.1, NetBSD 6.0(amd64 and evbarm), FreeBSD 9.0 and MacOS 10.8.2.