parser breaks with bad input

Reported at http://shriphani.com/blog/2012/10/24/dateutil-problems/

>>> dparser.parse("P 16:08 May 14, 2003 UTC", fuzzy=True)
Traceback (most recent call last):
File "", line 1, in
File "/usr/lib/pymodules/python2.6/dateutil/parser.py", line 697, in parse
return DEFAULTPARSER.parse(timestr, **kwargs)
File "/usr/lib/pymodules/python2.6/dateutil/parser.py", line 301, in parse
res = self._parse(timestr, **kwargs)
File "/usr/lib/pymodules/python2.6/dateutil/parser.py", line 557, in _parse
res.hour += 12
TypeError: unsupported operand type(s) for +=: 'NoneType' and 'int'