This does not go all the way, but helps improve the readability of the
algorithm a little bit and modernizes the code.
* src/field/FieldClassMatcher.js (constructor): Renamed from
`__constructor'.
(__constructor): Remove method.
(match): Extract most code into `#_reduceFieldMatches'.
(_reduceFieldMatches): New method, simplifying the algorithm slightly.
(_reduceMatch): Simplify.
* test/field/FieldClassMatcherTest.js: Update accordingly.
This is just to make sure that the current system is both well-understood
and does not break with changes. This is a very important class, as it
drives the display of the entire UI.
* test/field/FieldClassMatcherTest.js: New file.
Mike Gerwitz