COOSYS + STIL default VOTable output version

[Mark Taylor]

Hi apps.

TL;DR: does anyone mind if STIL starts writing VOTable 1.3
       instead of 1.2 by default?

In view of the recently-accepted VOTable 1.3 Erratum #1

   http://wiki.ivoa.net/twiki/bin/view/IVOA/VOTable-1_3-Err-1

I am making some changes to STIL (hence STILTS and TOPCAT)
to work better with COOSYS elements in VOTables.

Although in the immediate future neither STILTS nor TOPCAT will 
really behave differently in the presence of COOSYS elements,
since they do not try to understand coordinate systems
at that level, the current changes mean that they will:

  1. make it possible for users to see what COOSYS elements have 
     been attached to input VOTables

  2. write COOSYS elements out to VOTable documents when writing a
     (modified or unmodified) version of a StarTable that was read in
     as a VOTable with COOSYS elements
     (i.e. round-tripping VOTables through STIL's StarTable
     interface will not lose COOSYS information)

So STIL will now, in some circumstances, write VOTables containing
COOSYS elements.  Since the recent erratum un-deprecates COOSYS
at VOTable 1.3, but not VOTable 1.2, that means that if STIL
outputs VOTables of version 1.2, it is technically behaving in
a deprecated way.  By default, STIL has up till now written 
its VOTable output according to the VOTable 1.2 version 
(though this is configurable).

So, I plan to modify STIL (hence TOPCAT and STILTS) so that by
default the VOTable documents it outputs correspond to v1.3 of
the VOTable standard, instead of v1.2 as at present.

I don't expect this will cause anybody any trouble, but if you think 
it might do, or want to discuss it further, please get in touch.

Thanks for reading.

Mark

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/