New energetic particle precepitation schemes

### What is the feature/what would you like to discuss?

Source mods are in
```
/glade/work/ganglu/cam6_4_107/oct2003_new/SourceMods/src.cam
```
Gang's note:
The MEPED and SPE forcing files are totally independent of the standard high-latitude forcing files, and one can use any of the 3 electric potential and auroral inputs in conjunction of MEPED and/OR SPE drivers. I have put my data processing codes along with the original NOAA-MEPED and GOES-11 SPE data files under
```
/glade/work/ganglu/cam6_4_107/oct2003_files
```

### Is there anyone in particular you want to be part of this conversation?

@hanli-liu

### Will this change (regression test) answers?

No

### Will you be implementing this enhancement yourself?

Yes