Description: ./files directory cannot be up 32000 directories max at ext3 configuration.
Solution : split the uid case directory at 3 level to create a tree structure. Apply this new structure to all PM. Set a upgrade procedure at time to use processmaker upgrade <workspace> commnand as su.
The file workflow/engine/methods/tracker/tracker_ShowOutputDocument.php was incomplete, there were not some validations like versioning, and there were not taking into account the extension of the file to download. I add those validations, taking like example the file /workflow/engine/methods/cases/cases_ShowOutputDocument.php
