Issue28 normalize eof

This implements EOF normalization, as requested in #28 
I implemented it as a new command line option `--eof`, but one could also discuss if EOF normalization should be performed always when trimming white space.
The code that actually does the EOF normalization is 
```python
            while len(lines) > 1 and not lines[-1]:
                lines.pop(-1)
```
Must be that it is Friday. You are of course right. But I would probably add it to `trimWhitespace` as I can not think of somebody wanting to fix eof but leave trailing whitespaces in the file. Can you think of such a usecase?