make comments output more robust (#2633)...- improve handling of comments right after `return`
- retain comments after `OutputStream`
- preserve trailing comments
- fix handling of new line before comments
- handle comments around parentheses
fixes #88
fixes #112
fixes #218
fixes #372
fixes #2629
compress `apply()` & `call()` of `function` (#2613)...- `fn.apply(a, [ ... ])` => `fn.call(a, ...)`
- `fn.call(a, ... )` => `a, fn(...)`
where `fn` can be `function` literal or symbol reference linked through `reduce_vars`