[daip] FG tables

[Gustaaf van Moorsel]

I noticed TVFLG is creating a new FG table each time it is run.
For FLAGVER=0, the new table contains the flags in the existing
table, and adds the new flags to it.

This I believe is a change in behavior: for FLAGVER=0, TVFLG used
to add the new flags to the highest numbered existing FG table.

In contrast, UVFLG maintains the old behavior: for FLAGVER=0, it
does not create a new FG table, but adds flags to an existing
table.

Gustaaf