Taught IDLE's autoident parser that "yield" is a keyword that begins a stmt.  Along w/ the preceding change to keyword.py, making all this work w/ a future-stmt just looks harder and harder.
Taught IDLE's autoident parser that "yield" is a keyword that begins a
stmt.  Along w/ the preceding change to keyword.py, making all this work
w/ a future-stmt just looks harder and harder.

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