DataFrame.to_string ignores col_space when header=False
```
import pandas as pd
df = pd.DataFrame([[0,1,2]], index=['Sum'], columns=['A','B','C'])
print(df.to_string(col_space=20))
print(df.to_string(col_space=20, header=False))
```

Output:

```
                       A                    B                    C 
Sum                    0                    1                    2
Sum  0  1  2
```

(a minor irritation...)
