Message output

The oracdr infrastructure provides commands for primitive writers to print informational messages, warnings and error messages to the user. These commands are orac_print, orac_warn, and orac_err. In principal these commands can send information to different locations and this location is under the control of the person running the pipeline rather than primitive writer (using the -log option). The Perl print and warn commands should not be used since they always write output to standard output and standard error whereas the ORAC print commands can send to multiple filehandles.