Format affected rows and query time according to locale for better readability

[andialbrecht]

The number of affected rows and the execution time should be formatted according to the current locale to improve readability. Esp. thousands separators for the number of affected rows is useful when the query returns a lots of rows.

To get started:

>>> import locale
>>> locale.setlocale(locale.LC_ALL, 'en_US')
'en_US'
>>> locale.format("%d", 1255000, grouping=True)
'1,255,000'