fix highlighting of powershell v2 multiline comments

lib/ace/mode/powershell_highlight_rules.js

@@ -73,6 +73,10 @@ var PowershellHighlightRules = function() {
             {
                 token : "comment",
                 regex : "#.*$"
+            }, {
+                token : "comment.start",
+                regex : "<#",
+                next : "comment"
             }, {
                 token : "string", // single line
                 regex : '["](?:(?:\\\\.)|(?:[^"\\\\]))*?["]'
@@ -118,13 +122,21 @@ var PowershellHighlightRules = function() {
         ],
         "comment" : [
             {
-                token : "comment", // closing comment
+                token : "comment.end",
-                regex : ".*?\\*\\/",
+                regex : "#>",
                 next : "start"
             }, {
-                token : "comment", // comment spanning whole line
+                token : "doc.comment.tag",
                 merge : true,
-                regex : ".+"
+                regex : "^\\.\\w+"
+            }, {
+                token : "comment",
+                merge : true,
+                regex : "\\w+"
+            }, {
+                token : "comment",
+                merge : true,
+                regex : "."
             }
         ]
     };