Removed trailing white spaces

Removed trailing whitespaces with

```sh
for file in `grep -r " $" * | cut -d : -f 1 | sort | uniq | grep -v " "`; do sed -i 's/[ \t]*$//' $file; done
```

and some handwork.
Merge pull request #394 from tstorch/trailing_white_spaces

Removed trailing white spaces