Missing file upload error handling in modulemanager

Description:

I want to import the content of a module table using the module manager. The file size is greater than the configured maximum upload file size limit. The import falls back to the existing module data file instead of showing an appropriate error.

Steps to reproduce:

1. Import a CSV data file using the modulemanager, which is larger than the configured upload limit and differs from the current module data file content.
2. Inspect the database to find out the to be uploaded file content wasn't updated, but the existing module data file was used.

Additional Information:

In papaya_modulemanager.php:510ff $_FILES[$this->paramName] has to be checked for errors

A simple way to confirm the faulty behaviour is to activate the web developer console (FF) and note that path=module is passed to the xmlrpc request.

Note: How about adding the calculated upload file limit to the System Information screen?