Allow tabs as separators between attributes

[FliegendeWurst]

An example of this can be seen in the updated test :)

I am actually not sure whether this should be allowed or not..

[seanmonstar]

I somehow didn't notice this pull request, I'm so sorry!

Is there a situation you find where mime types include tabs? Quickly looking in the specs, it doesn't seem to mention tabs...

[FliegendeWurst]

I remember Yahoo returning some in their mail headers.

[seanmonstar]

I'd love to see an example, if you have one.

[FliegendeWurst]

Sadly I dont have an example anymore :(

[rustonaut]

Mime in Mail can actually have tabs in practice[1] (and "\r\n " / "\r\n\t" sequences if the content type is split over multiple lines...).

For mail " " is basically equivalent to "\t", so if a mail program does insert WSP before or after after the ";" having "\t" is totally possible, just a rare choice.

So supporting it is a good idea for robustness.

[1]: and I think in the standard too, just that you have to cross read more than one standard to be sure :=(