Synchronize glossary with py3k.
Synchronize glossary with py3k.

This update includes new entries that apply to 2.7 too, mention of class
decorators, mention of nonlocal, notes about bytecode, markup fixes and
some rewrappings.  Future backports of changes should be slightly
easier.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator