CDM reader - allow reading from multiple files
For some applications, it is handy to be able to load to a CDM table(s) instance the content of multiple files matching the same fileID pattern.
Currently this is disabled in the reader tool.
Also, the reader takes only one directory for the data path: check if the way files are parsed accepts lists of directories, wildcards, etc....
Some measure has to be taken so as not to load an excessively large amount of data, otherwise just let it fail if it does.