Use obj property access rather than Array#indexOf
In vttcue and vttregion, we were checking for some settings in an array
via indexOf but we can do the same via an object property access which
should be faster and also works in IE8.
Don't use forEach for looping over arrays
Use regular for-loop.
In one case, create an IIFE so that the variables will be
self-contained.
Merge branch 'ie8' into custom-build
Don't always use vttcue.js
Merge branch 'ie8' into custom-build
Always use vttcue.js