Meta data point locator JSON import backwards compatibility broken

[jazdw]

Previously meta data point locators were exported with "xid" as the property for the context point's XID. Now they are required to contain a "dataPointXid" property. This breaks backwards compatibility when importing old meta data point exports.

You will see a message like this

Data point 'DP_Cell_GPS': Missing 'dataPointXid' in context point

FYI I am fine to mark this as "wont fix".