Converter can't handle spaces in file/directory name

[Wessie]

The converter seems to unconditionally replace any spaces ( ) in the full path with underscores (_).

This simply produces the following traceback:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "build/bdist.linux-x86_64/egg/dejavu/control.py", line 40, in fingerprint
  File "build/bdist.linux-x86_64/egg/dejavu/convert.py", line 28, in find_files
OSError: [Errno 2] No such file or directory

[worldveil]

Agreed this was the silliest TODO I didn't incorporate, the underscores was just to make the names look prettier. If you pull request and fix I'd be happy to incorporate.