Aubit 4GL SVN-Code

Page and line tracking, the four margins, COLUMN positioning, SKIP, NEED,
page breaks, and the aggregates. A probe compares a report's output
against the C runtime line for line - nothing normalised, since a report
is entirely about column and page layout - and all 66 lines match.

The state follows BaseFGLReport from the original C# library, which had
the data model right even though the behaviour was never written. The
layout defaults were read out of the generated C rather than guessed:
page length 66, margins top 3, bottom 3, left 5, right 132.

COUNT(*) and SUM/AVG keep separate counters: COUNT counts rows while the
others only see non-null values, so a row with a NULL still counts but
does not drag the average down.