fix herestring highlighting in sh mode

lib/ace/mode/sh_highlight_rules.js

@@ -99,8 +99,12 @@ var ShHighlightRules = function() {
             }, {
                 defaultToken: "string"
             }]
-        },  {
+        }, {
+            regex : "<<<",
+            token : "keyword.operator"
+        }, {
             stateName: "heredoc",
+            regex : "(<<)(\\s*)(['\"`]?)([\\w\\-]+)(['\"`]?)",
             onMatch : function(value, currentState, stack) {
                 var next = value[2] == '-' ? "indentedHeredoc" : "heredoc";
                 var tokens = value.split(this.splitRegex);
@@ -113,7 +117,6 @@ var ShHighlightRules = function() {
                     {type:"string", value: tokens[5]}
                 ];
             },
-            regex : "(<<-?)(\\s*)(['\"`]?)([\\w\-]+)(['\"`]?)",
             rules: {
                 heredoc: [{
                     onMatch:  function(value, currentState, stack) {
@@ -131,7 +134,7 @@ var ShHighlightRules = function() {
                 }],
                 indentedHeredoc: [{
                     token: "string",
-                    regex: "^ +"
+                    regex: "^\t+"
                 }, {
                     onMatch:  function(value, currentState, stack) {
                         if (value === stack[1]) {
@@ -178,7 +181,7 @@ var ShHighlightRules = function() {
             regex : integer + "\\b"
         }, {
             token : keywordMapper,
-            regex : "[a-zA-Z_$][a-zA-Z0-9_$]*\\b"
+            regex : "[a-zA-Z_][a-zA-Z0-9_]*\\b"
         }, {
             token : "keyword.operator",
             regex : "\\+|\\-|\\*|\\*\\*|\\/|\\/\\/|~|<|>|<=|=>|=|!="