Make |, \lvert, \rvert work

Test Plan: .

Reviewers: xymostech

Reviewed By: xymostech

Differential Revision: http://phabricator.benalpert.com/D33

MJLite.js

@@ -30,7 +30,7 @@ var MJLite = (function() {
             var className = "mbin";
             if (prev == null || prev.type === "bin" || prev.type === "open") {
                 group.type = "ord";
-                elem.className = "mord";
+                className = "mord";
             }
             return makeSpan(className, textit(group.value));
         } else if (group.type === "sup") {
@@ -64,7 +64,9 @@ var MJLite = (function() {
     var charLookup = {
         '*': '\u2217',
         '-': '\u2212',
-        'cdot': '\u22C5'
+        'cdot': '\u22C5',
+        'lvert': '|',
+        'rvert': '|'
     };
 
     var textit = function(value) {

parser.jison

@@ -7,7 +7,9 @@
 \s+                   /* skip whitespace */
 cdot                  return 'CDOT'
 frac                  return 'FRAC'
-[/a-zA-Z0-9]          return 'ORD'
+lvert                 return 'LVERT'
+rvert                 return 'RVERT'
+[/|a-zA-Z0-9]         return 'ORD'
 [*+-]                 return 'BIN'
 \^                    return '^'
 [_]                   return '_'
@@ -66,6 +68,10 @@ func
         {$$ = [{type: 'bin', value: yytext}];}
     | 'FRAC' group group
         {$$ = [{type: 'frac', value: {numer: $2, denom: $3}}];}
+    | 'LVERT'
+        {$$ = [{type: 'open', value: yytext}];}
+    | 'RVERT'
+        {$$ = [{type: 'close', value: yytext}];}
     ;
 
 atom