There are two changes:
First - The flash-delay option is for how until the parens that are highlighted will stop highlighting. The flash-delay option for the ParenMatch only affects the 'default' style. Similarly the 'expressions' style does not use the flash-delay option and will not stop highlighting until input is given to IDLE. Desired behavior is for the flash-delay option to work for both styles, and setting flash-delay to 0 will cause the input required behavior that is currently only used by the 'expressions' style. 

I couldn't find anything in the test suite for testing the delay behavior specific to styles, only that the timer works in general, so I'm not sure how to test it other than just observing it. The test did not seem to cover if 'default' style worked properly using the 'show surrounding parens' command. I have added that to all style tests.

Second - There is no style for highlighting the opening and closing parens. The new behavior is to write 'parens' (without ticks) for the style option, apply/ok the options, restart IDLE, and make a statement with parens, and it highlights both parens. 

The uploaded parenmatch test file covers the parens style, ensuring it works correctly.