#14434: make tutorial link in 'help' banner version-specific
#14434: make tutorial link in 'help' banner version-specific

Without this fix, both 2.7 and 3.x would always point to the "current"
docs...which means that before this fix python 3.2 'help' pointed to the 2.7
tutorial, and without this fix when we switch over to the 3.x docs being
current, 2.7 would have pointed to the python3 tutorial.

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