Port reviewDialogView.js to ES6.
Review Request #8543 — Created Nov. 16, 2016 and submitted
In preparation for some minor cleanups to the markup and style to fix
regressions introduced by the review changes I made earlier, I've converted
this file over to ES6.
Ran js-tests.
Tool: Pyflakes Processed Files: reviewboard/staticbundles.py Ignored Files: reviewboard/static/rb/js/views/reviewDialogView.es6.js Tool: PEP8 Style Checker Processed Files: reviewboard/staticbundles.py Ignored Files: reviewboard/static/rb/js/views/reviewDialogView.es6.js