parses the header line from a .koc file. This is the line that specifies things such as the file version, and the name and version of the offline circulation tool that generated the file. See http://wiki.koha-community.org/wiki/Koha_offline_circulation_file_format for more information.
pass in a string containing the header line (the first line from th file).
returns a hashref containing the information from the header.
fetches the names of the columns (and function arguments) found in the .koc file for a particular command name.
For instance,
the issue command requires a cardnumber and barcode.
In that case this function returns a reference to the list qw( cardnumber barcode ).
parameters: the command name
returns: listref of column names.
pass in a barcode get back the borrowernumber of the patron who has it checked out. undef if that can't be found