* handle cusor position relative to comments correctly
* use more robust method of cursor offset tracking
* add support for cursorOffset with rangeStart/End
* add tests for cursorOffset
* use old JS syntax for node4
* add another cursor offset test case
* remove trailing whitespace in cursor tests
* fix null findNodeAtOffset handling
* remove dead code
* add more test cases
* use indexOf for node4
* revert comments.js
* add more comment tests
* change tests infra
* Fix AST_COMPARE
* move CURSOR to top level of file
* mutate result
* use es6 property shorthand
* simplify diff offset calculation
* put remaining test cases in individual files