Update information about __del__() & reference cycles for CPython. This partially fixes SF bug #492619.
Update information about __del__() & reference cycles for CPython.
This partially fixes SF bug #492619.

Fix a typo & use the new notice environment instead of (ab)using the \note
and \warning macros.

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