[NuTool - ClockConfigure] [NuTool - PinConfigure] implement Ctrl-S to save and remember file name

[jaydcarlson]

In both the ClockConfigure and PinConfigure tool, hitting Ctrl-S does nothing, and hitting on the "Save" icon always invokes a file chooser. These apps should remember the file that was opened and when the Save button is pressed, write to that same file. An alternate "Save As" button could be implemented to change the file path.

Additionally, Ctrl-S should bind to this "Save" command, as it does in 99% of other Windows applications.