Release 2.2.2

• Add correct wrapping for C++-instantiated objects available through global registries, e.g. when loading an XML file. The objects are decorated with the python functions when accessed through the global registries GetObj()
• Moved global object registries to pyobjcryst.globals
• Fix powder pattern plot issues (NaN and update of hkl text with recent matplotlib versions)
• Fix access to some polyhedra types
• Update documentation