Mass update: replace g.choose by corresponding ternary operator in Leo's core files using a script.  All unit tests pass and pylint is happy.
Completed mass conversion of g.choose to Python's ternary operator.  All unit tests pass and pylint is happy.
Completed the removal of g.choose from Leo's core.  This required a change to the "@button replace g.choose" script.  All unit tests pass and pylint is happy.