Bug 1466727 part 5. Stop using nsITreeColumn in toolkit. r=mossop

I had to do window.TreeColumn instead of just TreeColumn to work around eslint
being buggy.  That bug is tracked in bug 1466842.

toolkit/content/widgets/tree.xml

@@ -336,8 +336,8 @@
               return false;
             if (row < 0 || row >= this.view.rowCount || !column)
               return false;
-            if (column.type != Ci.nsITreeColumn.TYPE_TEXT &&
-                column.type != Ci.nsITreeColumn.TYPE_PASSWORD)
+            if (column.type != window.TreeColumn.TYPE_TEXT &&
+                column.type != window.TreeColumn.TYPE_PASSWORD)
               return false;
             if (column.cycler || !this.view.isEditable(row, column))
               return false;
@@ -1128,7 +1128,7 @@
              if (cell.col.cycler) {
                view.cycleCell(cell.row, cell.col);
                return;
-             } else if (cell.col.type == Ci.nsITreeColumn.TYPE_CHECKBOX) {
+             } else if (cell.col.type == window.TreeColumn.TYPE_CHECKBOX) {
                if (this.parentNode.editable && cell.col.editable &&
                    view.isEditable(cell.row, cell.col)) {
                  var value = view.getCellValue(cell.row, cell.col);
@@ -1222,7 +1222,7 @@
         // mousedown and the time we click, don't fire the select handler.
         // see bug #92366
         if (!cell.col.cycler && this._lastSelectedRow == cell.row &&
-            cell.col.type != Ci.nsITreeColumn.TYPE_CHECKBOX) {
+            cell.col.type != window.TreeColumn.TYPE_CHECKBOX) {
 
           var cellSelType = this.parentNode._cellSelType;
           if (cellSelType == "text" && cell.childElt != "text" && cell.childElt != "image")