Handling Ctrl-C so it interrupt gdb instead of killing agdbentures
Ctrl-C should be passed to gdb instead of killing agdbentures.
Need to differentiate when gdb is running or not? When gdb is running the inferior, Ctrl-C must interrupt it. When it is not, gdb just prints 'Quit'. We should detect this to allow quitting agdbentures e.g. if Ctrl-C was pressed twice in quick succession?