Added level-select and gold-rank info after completing a course — Joon Shining Steam update #266642

A few quality-of-life updates in the course-select screen: • after completing a course, when you return to the course-select scene you can select individual levels, see what your last rank was for each level, and any individual level again. This more easily allows you to try for gold in each level, and go back to search for droplets and other secrets • after completing a level, if you've previously completed its parent-course you have the option to exit back to course select (eg if you just wanted to get gold on a specific level, then return to course select and go to an unrelated level) • on the course-select screen, after completing a course you can see how many gold ranks you have total for that course In the levels: • we've removed most of the pesky pinball-flippers from world 1 and 2, which never really worked quite right