Remove Python factory functions for ObjCryst wrappers.
Avoid crash for "scons -h" which skips SConscript.configure.

env['has_objcryst'] would be undefined in one of sconscripts.
Avoid use of Python structure objects in testing.

Replace CIF files with PDFFit formatted stru files that can
be loaded with loadTestPeriodicStructure.  Create dummy class
for testing NoMetaStructureAdapter.
Removed unused header.

Python functions not used anymore in testing.
Remove DiffPyStructureAdapter class.

Not used anymore.
Remove factory/registry for Python-based adapter.

This was moved to diffpy.srreal.
Remove final Python dependencies.

No need to link to boost_python anymore!