Fix Registry download count number accuracy issue

Use the same path to the download data file for all functions and remove the file after uploading. This should prevent old data from being uploaded again. This issue happened only, when the script was executed as a cronjob.
Since the script created the data file in a location relative to the current working directory, but tried to load the file relative to the script file for uploading. When running as a cron job, the current working directory was the users home directory, but the script was located somewhere else. Since there was an old data file next to the script, this file got uploaded every time the cron job was executed.
`__dirname` doesn't vary while this is running, right? should `datafilePath()` just be a var rather than a function?