Preserve SPF evaluation order

[kenmortimer]

Currently the parsed SPF terms are listed according to their directive's qualifier or modifier name.

As SPF records are evaluated left-to-right [RFC 7208 4.6.2], this output format loses information. It would be useful for the structured output to preserve the actual order of the terms.

The current format also ignores that the include mechanism may be prefixed with a qualifier [RFC 7208 5.1 (4)].

[seanthegeek]

I'm finally getting around to improving this project. It will take some rewriting to get the output right. Not sure when I'll have time, but it's on my todo list.