20111109
========

Continued to work on the 
:mod:`lino.utils.bcss` 
and
:mod:`lino.utils.xmlgen` 
modules.

20111103: i misunderstood the concept of namespaces.
it *is* possible to have multiple ocurences of 
the same element name at different places in a tree. 
example:

  IdentifyPersonRequest
    PersonData
        LastName
    PhoneticCriteria
        LastName

new version: `parent` is being set at instantition.
the namespace of an Element 
defaults to the namespace of its parent.

Both modules' doctests now work again. Check-in 20111109.