add Switch input and output
Changed switchin to have getBus1() and getBus2()
Added a refresh() call.
Added PsseModelException
Added Gen modes
Added isEnergized(ndx)
Cleaned up interaction with generators
Add sublists and a sublist wrapper for switches for bus equipment.
Fixed missing _switches link.
Added ability to get the island for a node.
merge dev branch to master
start to clean up lists for new scheme
list reorg