Highlight NULL instead of null in C/C++

CodeMirror C and C++ currently highlight the string "null", which isn't defined in C/C++. Those languages do macro "NULL", though.

Author: vincentwoo

mode/clike/clike.js

@@ -374,7 +374,7 @@ CodeMirror.defineMode("clike", function(config, parserConfig) {
     blockKeywords: words("case do else for if switch while struct"),
     defKeywords: words("struct"),
     typeFirstDefinitions: true,
-    atoms: words("null true false"),
+    atoms: words("NULL true false"),
     hooks: {"#": cppHook, "*": pointerHook},
     modeProps: {fold: ["brace", "include"]}
   });
@@ -390,7 +390,7 @@ CodeMirror.defineMode("clike", function(config, parserConfig) {
     blockKeywords: words("catch class do else finally for if struct switch try while"),
     defKeywords: words("class namespace struct enum union"),
     typeFirstDefinitions: true,
-    atoms: words("true false null"),
+    atoms: words("true false NULL"),
     dontIndentStatements: /^template$/,
     isIdentifierChar: /[\w\$_~\xa1-\uffff]/,
     hooks: {