* Due to popular request (well, someone told me that someone else wanted it), I added a pid column, hidden by default.

* Because the number of columns changed, saved heading data is no longer valid, so save a 'header data version number' in the config files, to keep track of that.

* Add a "Programs Only" option. This only shows processes that have a GUI, or are attached to a tty. This works better than I expected :)