Change Sequence elements to allow a namespace when serialising
This is a bit of foundation work for adding support for some ExtensionList extensions (in this case, support for a sequence containing xm:f elements as found in the x14:cfRule element)
This is a bit of foundation work for adding support for some ExtensionList extensions (in this case, support for a sequence containing xm:f elements as found in the x14:cfRule element)