TinyMCE: counter support (may not be 100% exact match to server-side count, but there's already discrepencies due to URL shortening)

Fix for bad char conversions also, caused short text to not be saved in some cases.

js/util.js

@@ -110,7 +110,7 @@ var SN = { // StatusNet
                 return;
             }
 
-            var remaining = MaxLength - form.find('#'+SN.C.S.NoticeDataText).val().length;
+            var remaining = MaxLength - SN.U.CharacterCount(form);
             var counter = form.find('#'+SN.C.S.NoticeTextCount);
 
             if (remaining.toString() != counter.text()) {
@@ -134,6 +134,10 @@ var SN = { // StatusNet
             }
         },
 
+        CharacterCount: function(form) {
+            return form.find('#'+SN.C.S.NoticeDataText).val().length;
+        },
+
         ClearCounterBlackout: function(form) {
             // Allow keyup events to poke the counter again
             SN.C.I.CounterBlackout = false;