Fortify logic per #19 and amend comments

See #19. Fixes #17 too. I amended the [closure comments](https://developers.google.com/closure/compiler/docs/js-for-compiler) and made it all safe to compile in advanced mode. Itemized changes are in my [solid branch](https://github.com/ryanve/ender-js/commits/solid). I left an .x in the version number b/c I didn't know if I should bump it.