add getNull, add compatibility mode for mattn/sqlite3

Created by: steffengy

Early feedback please ;)

This adds the following internally used query parameters:

• _mattn: Enables the compatibility mode when set to "true"
• _loc: Enable time.Time handling and set the locale for it This is enabled by setting a locale e.g. _loc=auto for the current systems locale. This only works when _mattn is specified.