Completes James' TimeConverter work
This completes the work that James started. It moves most of the non-GUI
related processing from TimeTextCtrl to James' TimeConverter class.
Other changes include:
1) TimeTextCtrl now expects the format name instead of the format string to be
passed when creating a new instance. I found that almost all cases created the
instance with a blank format string and then set the string after creation.
2) To simplify maintenance and prevent a possible discrepancy between the two,
Increase() and Decrease() were merged into a single routine.
As a result:
1) All cases where a TimeTextCtrl was being used to extract information and
not actually display a control have been changed to use TimeConverter instead.
2) All cases where TimeTextCtrl was being created with an empty format and
then immediately followed by something like this:
tt.SetFormatString(tt.GetBuiltinFormat(c->GetFormat()))
have been changed to pass the format name instead of the format string when
creating the TimeTextCtrl instance.