Adding isReorderable column property, to be able to turn off reordering for certain columns.

Author: tchoiSchrodinger

src/FixedDataTableCellGroup.react.js

@@ -117,7 +117,7 @@ var FixedDataTableCellGroupImpl = React.createClass({
       this.props.onColumnResize;
     var onColumnResize = cellIsResizable ? this.props.onColumnResize : null;
 
-    var cellIsReorderable = this.props.onColumnReorder && rowIndex === -1 && columnGroupWidth !== columnProps.width;
+    var cellIsReorderable = columnProps.isReorderable && this.props.onColumnReorder && rowIndex === -1 && columnGroupWidth !== columnProps.width;
     var onColumnReorder = cellIsReorderable ? this.props.onColumnReorder : null;
 
     var className = columnProps.cellClassName;

src/FixedDataTableColumn.react.js

@@ -156,6 +156,15 @@ var FixedDataTableColumn = React.createClass({
      */
     isResizable: PropTypes.bool,
 
+    /**
+     * Whether the column can be dragged to reorder.
+     *
+     * This property only provides the UI for the column reordering. If this
+     * is set to true, you will need to set the onColumnReorderEndCallback table
+     * property and render your columns appropriately.
+     */
+    isReorderable: PropTypes.bool,
+
     /**
      * Whether cells in this column can be removed from document when outside
      * of viewport as a result of horizontal scrolling.