(CFACT 119) Add zone facts for solaris

This patch adds zone facts for solaris. Since zones do not provide a C API, we
use zone commands to fetch this information.
@MikaelSmith I haven't added these as structured facts, since in facter 2.2, the zone properties are printed as flat facts in this fashion.
```
| facter -y | grep zone
zone_global_brand: native
zonename: global
zone_global_name: global
zone_global_status: running
timezone: PDT
zone_global_path: /
zone_global_uuid: ""
zone_global_id: "0"
zones: 1
zone_global_iptype: shared
```