Replacement of `\ufe33` and `\ufe34` are implemented, but not-quite-there due to existing `_`s not being encoded properly. This is hard to fix since finalEncode seems to be getting applied multiple times on the same input, resulting in double escaping
shortened internal names
shortened internal names further, by scoping freshNames on a method-by-method basis
shortened class headers don't work
better genInstanceTestMethods works
Stuff works under optimizeJS
added ScalaJS.extends({}) back in