Don't force a default value in a format function

This seems like a more sane fix to so many of the bugs related to default values. If
someone really wants to make 0, 0.00, etc. the default let them force it via the "Default
Value" attribute
That's removing the crux of all of these issues.  0, '0', 0.00,' '0.00' are all legit values in many contexts.  '', null, and array() are not valid.

The problem was that the function format was making up values to return, when really it shouldn't have been trying to format a null value.