Finally, using the dotlrn user folder to store attachments wasn't the initial behavior. Initially attachments was using the file-storage folder mapped to it. I rolled back to that. I took advantage to improve the UI somewhat.
Attachments provides a Tcl API to map a folder attachments::map_root_folder -package_id package_id -folder_id folder_id.
Now attachments can potentially be used without dotlrn (I have tested it with forums on core).
Still to do:
Forums will use attachments if it is mounted as a child node and with the name "attach" (hard coded). That needs to be fixed in forums.
