Experimental cross reference changes
Merge remote-tracking branch 'origin/master'

Conflicts:
	build/doctrees/diagnostics.doctree
	build/doctrees/environment.pickle
	build/doctrees/lifetimes.doctree
	build/html/ContextDependentExtensions.html
	build/html/InterceptionExtensions.html
	build/html/RuntimeDecorators.html
	build/html/_sources/diagnostics.txt
	build/html/_sources/lifetimes.txt
	build/html/appendix.html
	build/html/lifetimes.html
	build/html/objects.inv
	build/html/searchindex.js
	source/lifetimes.rst