Support Unicode Negated Relations (#952)

* Support Unicode Negated Relations

This is the fifth in a series of PRs to give KaTeX the ability to recognize Unicode character input.

All the characters in this PR will produce `rel` atoms.

* Add parse tests

* Fix AMS functions

Fix a brain cramp.

* Add internal aliases to code comments

test/katex-spec.js

@@ -2626,6 +2626,10 @@ describe("Unicode", function() {
         expect("ΓΔΘΞΠΣΦΨΩ").toParse();
     });
 
+    it("should parse negated relations", function() {
+        expect("∉∤∦≁≆≠≨≩≮≯≰≱⊀⊁⊈⊉⊊⊋⊬⊭⊮⊯⋠⋡⋦⋧⋨⋩⋬⋭⪇⪈⪉⪊⪵⪶⪹⪺⫋⫌").toParse();
+    });
+
     it("should parse relations", function() {
         expect("∈∋∝∼∽≂≃≅≈≊≍≎≏≐≑≒≓≖≗≜≡≤≥≦≧≫≬≳≷≺≻≼≽≾≿").toParse();
     });