OMP ACSIS data retrievals

Last week we had a strange problem where data could be retrieved from the OMP from November onwards but between Feebruary and October 2007 data retrievals failed because the OMP sent the wrong filenames to CADC. Turned out that the new test database (running Sybase 15) had been loaded with data up to end of October and that was triggering a new logic path through the OMP. Usually, the OMP failed to find any entries in the database and fell back to looking on the data disk for raw data. This always works and always finds the right files. When rows are found in the database there is no need to look on disk (the database is much faster than looking at files) and once the test database was initialised the DB lookups were working properly. The only problem was that the query to the ACSIS database did not return the filename information from the FILES table and therefore the OMP was forced to guess the filename. For data taken since we renumbered the subystem numbers the guess was wrong and CADC were asked to serve files that didn't exist.

I fixed the problem last week and now retrievals work with database and file lookup. I was able to cleanup quite a lot of code in the process and the Astro::FITS::HdrTrans module was made a little cleverer and can now tell the difference between a database result and a header read from a file. Apologies to people who experienced retrieval problems over the past 2 weeks.