Add context menu option to system message window to send ^C to the application, primarily as an aid to developers who may face the need to abort in awkward situations during testing. Unlike hitting ^C on the keyboard, this method bypasses restrictions on the keyboard mode—i.e. locked or local mode only. In the ATE case, it also discards any currently queued output, allowing the effect of the ^C to be seen more rapidly in the output.
Note that sending a ^C doesn't necessarily always abort the application. Possible exceptions would be where the applicaton has disabled it, or is trapping and resuming from it, or is in the middle of a GUI wait state.
Also note this may leave the terminal in an indeterminate state requiring you to use the Settings menu to manually clear the kbd lock and/or reset the terminal, but but helps to work around situations where a combination of rapid output and a keyboard lock makes it otherwise impossible to abort an out-of-control program.
