Fix: Column sorting classes might not be applied correctly

- If you use multiple column definations such that a columns' sorting
  options are initially disabled and then enabled, the sorting classes
  for the header were not being applied correctly.

- The fix is to always assign classes based on the most up-to-date
  information for the column.

- This fixes DataTables/DataTables #303

.datatables-commit-sync

@@ -1 +1 @@
-fd6a64289e82e811d542745a632496ded845f90c
+49c27c14b0bd6fee5b1d4e26d9a5ede0f36d4867

media/js/jquery.dataTables.js

@@ -516,8 +516,6 @@
 		var oDefaults = DataTable.defaults.column;
 		var iCol = oSettings.aoColumns.length;
 		var oCol = $.extend( {}, DataTable.models.oColumn, oDefaults, {
-			"sSortingClass": oSettings.oClasses.sSortable,
-			"sSortingClassJUI": oSettings.oClasses.sSortJUI,
 			"nTh": nTh ? nTh : document.createElement('th'),
 			"sTitle":    oDefaults.sTitle    ? oDefaults.sTitle    : nTh ? nTh.innerHTML : '',
 			"aDataSort": oDefaults.aDataSort ? oDefaults.aDataSort : [iCol],
@@ -671,6 +669,11 @@
 			oCol.sSortingClass = oClasses.sSortableDesc;
 			oCol.sSortingClassJUI = oClasses.sSortJUIDescAllowed;
 		}
+		else
+		{
+			oCol.sSortingClass = oClasses.sSortable;
+			oCol.sSortingClassJUI = oClasses.sSortJUI;
+		}
 	}