make easier to parse european-style dates in to_csv
Again from mailing list:

Example:
data1 = '''date;value
01/05/2010;1
15/05/2010;2
31/05/2010;3
'''

df = pd.read_csv(StringIO(data1),sep=";",converters={'date':pd.datetools.dateutil.parser.parse})
print df.to_string()

Returns the first row wrong:
                  date  value
0  2010-01-05 00:00:00      1
1  2010-05-15 00:00:00      2
2  2010-05-31 00:00:00      3

df = pd.read_csv(StringIO(data1),sep=";",converters={'date':lambda x: pd.datetools.dateutil.parser.parse(x, dayfirst=True)})
print df.to_string()

Returns the correct output
                  date  value
0  2010-05-01 00:00:00      1
1  2010-05-15 00:00:00      2
2  2010-05-31 00:00:00      3

When using index_col and parse_dates, you can get also some of the dates that are wrong, some of them correct.

df = pd.read_csv(StringIO(data1),sep=";",index_col=[0],parse_dates=True)
print df.to_string()

Returns the first line also wrong:
            value
date  
2010-01-05      1
2010-05-15      2
2010-05-31      3
