Update py-gnosis-utils to 1.2.2.

While here,
* set LICENSE=public-domain
* no need to buildlink with obsolated py-xml, add py-expat to DEPENDS instead.
* distutils pkg, switch to use lang/python/distutils.mk.

from ANNOUNCE:

Gnosis Utils 1.2.2

  This release contains a bugfix in xml.pickle for mx.DateTime.

Gnosis Utils 1.2.1

  This release contains a minor bugfix in xml.pickle.

Gnosis Utils 1.2.0

  This release of the Gnosis Utilities contains several new modules,
  as well as fixes, enhancements, and speedups in existing
  subpackages.

(obache)