[bananas] FITAB error

[Eric Greisen]

An egregious error in FITAB has been discovered.  FITAB selected a bad
LUN for the input data file (16).  This LUN was used by low level
routines and the error "already open in FTAB" was deliberately
ignored.  The result was that the beginning of the input UV data was
overwritten by a small scratch file.  This only occurred for UV data
when NPIECE > 1, the data set was in time order, and some of the
tables with a TIME column were not sorted in time order.  This arose
fairly normally in VLBA processing when there is > 1 input data file.
Some of the tables, such as WX, would not be sorted in normal
processing, causing FITAB to invoke the sort routines.

In 31DEC99, a global search was conducted to find all places which
ignore the "already open in FTAB" condition and to remove this
tolerance of error.  The LUN (variable DLUN) in FITAB was also changed
to 26.

A patch for 15OCT99 has been issued.  Users of older systems might
consider editing FITAB, if present, changing the DLUN = 16 statement
to DLUN = 26.  Better yet, upgrade to 31DEC99.

Eric Greisen