Edit Edge Connectors - Improve Editing

[cube1us]

Edit Edge Connectors could do a better job of editing:

• Checking for invalid Pins
• Checking for invalid rows (machine dependent) [e.g. "V" and "P"]
• Checking for connector conflicts within the page being editing would catch some errors, too

[cube1us]

As it turns out, it was already checking for invalid Pins. I added a check for invalid rows and columns using the new IBMSMSPackaging class. I decided against checking for connector conflicts, however, as that would then require that information already exist, and checking for invalid rows and columns will catch quite a lot.