Changes to FGM panels on summary plots

[jameswilburlewis]

From Vassilis:

Jim, can we instead just plot the FGM spin fits in the overview plots in DSL coordinates? Change the “ysubtitle” to “DSL” instead of “GSE”. We should keep the limits to [-100,+100]nT as usual in the overview plots. We should also tclip the FGS spin axis (outside +/-100nT) from the overview plots (also in the multi-spacecraft FGM plots for TH-E should also be changed to DSL in similar fashion – sorry for the trouble).

[jameswilburlewis]

This should be for THEMIS-E only....showing the data in DSL is confusing for the ARTEMIS probes, which are 'upside down'...