Corrected the net logic and fixed an NPE in the Toggle command.

[rhauch]

These are the changes we made tonight to get the nets to work. Without these changes, when the nets were somewhere between open and closed, pressing the net button would result in an unknown state in the Toggle command and an NPE in the console print statement, making the entire robot inoperable.

This code was tested on a a few commits earlier than the latest master, so strictly speaking this commit against current master is untested. The differences in the 'master' branch are quite minor and unrelated, so I expect it to work. It can be merged after competition, though. (And we'll probably want to tag it after we know it works.)