PR# 17701 Wrong name on Editor tab in non Basic Text format after recompile

If the Editor is targeted to a cluster and the Editor format is not
Basic Text view, clicking on Compile changes the Editor contents to a class
but the Editor tab still shows the name of the cluster.

Pick a class TEST2 and drop in an Editor.
Select Flat view in Editor.
Pick cluster named "hamster" from Groups tool and drop in Editor.
Editor tab correctly shows cluster icon and name "hamster".
Note that the format is still Flat view.
Click on Compile.
The contents of the Editor now shows class TEST2  but the tab still shows a
 cluster icon and the name "hamster", instead of a class icon and name TEST2.