Teach all non-daemon scripts how to cleanly exit on CTRL-c

Using: raise SystemExit('some message')

is equivalent to:
sys.stderr.write('some message\n')
sys.exit(1)

scripts/salt

@@ -14,4 +14,7 @@ def main():
     client.run()
 
 if __name__ == '__main__':
+    try:
         main()
+    except KeyboardInterrupt:
+        raise SystemExit('\nExiting gracefully on Ctrl-c')

scripts/salt-call

@@ -15,4 +15,7 @@ def main():
     client.run()
 
 if __name__ == '__main__':
+    try:
         main()
+    except KeyboardInterrupt:
+        raise SystemExit('\nExiting gracefully on Ctrl-c')

scripts/salt-cp

@@ -14,4 +14,7 @@ def main():
     cp_.run()
 
 if __name__ == '__main__':
+    try:
         main()
+    except KeyboardInterrupt:
+        raise SystemExit('\nExiting gracefully on Ctrl-c')

scripts/salt-key

@@ -14,4 +14,7 @@ def main():
     saltkey.run()
 
 if __name__ == '__main__':
+    try:
         main()
+    except KeyboardInterrupt:
+        raise SystemExit('\nExiting gracefully on Ctrl-c')

scripts/salt-run

@@ -14,4 +14,7 @@ def main():
     client.run()
 
 if __name__ == '__main__':
+    try:
         main()
+    except KeyboardInterrupt:
+        raise SystemExit('\nExiting gracefully on Ctrl-c')