Reader: always read in lat and lon info for data probe #116

When using the new "hover over" data probe, if I load only one field from a data file (like i_vmr_num_a1_preAerMic in the screenshot below), then, in the tooltip, I do not get lat, lon values, although there is an area value listed. I guess this is because by default, the Reader always reads in area (for the calculation of global averages), but it does not read lat or lon unless the user explicitly chooses these variables using the Variable Selection control panel.

Could we revise the Reader so that lat and lon are always read in? Thank you!