Batch Tool: Implement versioning for the batch tool settings file

[lbross]

How sophisticated to you want this to be? I can detect if the local version is older than the server version and overwrite it. There is the possibility that the analyst will have updated the local file with the batch tool settings and this will overwrite their changes. I can pop a warning allowing the analyst to abort the process before it overwrites their changes. And/or I could make a backup copy of the existing local file in case the analyst wanted a record of their customizations.

The code that checks this runs when an AOI is selected. If someone were using the batch tool and we choose to go with the warning message, this should only happen on the first AOI because the process would either be aborted or the settings file would be brought up-to-date. Or perhaps we are overthinking this and there aren't going to be many customizations?