#1047 New Pydev Module doesn't check if file exists

[Leo Shklovskii]

Pydev 1.5.3.1260479439

Repro:

Right click in the project to create a new Pydev Module, for example bar
You'll get a new editor with the prefilled default text (created on, @author, etc.)
Save it
Right click in the project again to create a new Pydev Module with the same name - bar

Expected behavior:
Error/warning in the create new Pydev Module window that prevents you from finishing that dialog box

Actual behavior:
Dialog completes successfully, bar.py now contains the default text twice