Eliminate hard-coded configuration file from update script

[confluence]

The update script should not use a hard-coded configuration file location for the update settings. This makes it impossible to integrate it with beta packages which have a custom config location without manual intervention from the user.

Ideally the script should not be doing this parsing at all. My suggestion would be to move this functionality into the CARTA backend, which should be able to locate its own configuration directory. The backend should check these settings and then possibly launch the script only if it is required. This would require changes to the backend so that it is able to access the frontend preferences file.

A simpler option would be to add a custom config file parameter to the existing script, and to patch the existing backend launcher script in the beta packages. I would prefer to eliminate the parsing component of the script entirely, but if we run out of time before the next release this could be a fallback solution.