Add function to load SI data
Add documentation for load_si_data()
Remove underscores from option name
Update load_si_data() to handle other kinds of file and also return path
Add port of plot3d.APResult
Merge pull request #25 from ajdm/si_data

Add function to load SI data
Merge pull request #27 from ajdm/plot3d.APResult

Add port of plot3d.APResult