Log Message:
textproc/xmlada: Update from version 4.2.0.0 to version 4.4.0.0

Full change text can be found in features-XX in the distfile, but the
main changes are:

NF-440-LB01-017 attributeGroup support in simple type extensions (2012-11-08)
NF-43-KC20-003 License updated to GPL3 (2011-12-20)
NF-43-KC07-033 Documentation converted to Sphinx (2011-12-08)
NF-43-KC01-026 Schema: Ignore unsupported xsd:unique (2011-12-01)
NF-42-K708-021 Schema: Improved multi-tasking support (2011-07-26)
NF-42-K429-012 Schema: Ignore unsupported schema elements (2011-08-16)
NF-42-J818-003 New input source for streaming sockets (2010-12-16)