Ignore default namespace for attribute prefixes

[draivin]

Attribute prefixes should ignore the current default namespace, see
https://stackoverflow.com/questions/3312390/xml-default-namespaces-for-unqualified-attribute-names

I've made a quick implementation by adding a bool to the related methods and setting it to true when dealing with attributes, but I feel this is somewhat dirty, if you have any preferences please let me know.

[shepmaster]

but I feel this is somewhat dirty

Yeah, boolean arguments always give me that feeling too! However, I think it's the right thing to do to get the fix and test in. Can always see if a better solution raises its head later.

[shepmaster]

Thank you!