fix bug 1035946 - urllib.unquote does not like ints, and backslash will

wreak havoc with the CSV->postgres import
The reason the ```SyntaxError``` is complaining about the continuation character is because if you follow the first ```\``` as escaping the ```'```, you can see the above is equivalent to writing:
```
'foo'.replace("', "\\')
```
Which is of course totally not what is meant at all! In fact since it's not part of a string, now the first ```\``` encountered is being treated as the line continuation character.