Add an empty debug.log to package examples/ directory so that it uninstalls cleanly in case examples were launched

```
Modify setup.py on both Linux/Windows and debug.log in these locations:
  cefpython3/ <-- cefclient.exe
  cefpython3/examples/
  cefpython3/examples/wx/
```

Original issue reported on code.google.com by `czarek.t...@gmail.com` on 4 Dec 2014 at 4:19
