Add visual or audible alert support on connect/disconnect

The feature is detailed via the following option:

 --alert none|bell|blink

     Set alert action on connect/disconnect.

     It will sound the bell once or blink once on successful connect.
     Likewise it will sound the bell twice or blink twice on disconnect.

     Default value is "none" for no alert.

src/bash-completion/tio.in

@@ -29,11 +29,12 @@ _tio()
           -L --list-devices \
           -c --color \
           -S --socket \
+          -x --hexadecimal \
           -r --response-wait \
              --response-timeout \
              --rs-485 \
              --rs-485-config \
-          -x --hexadecimal \
+             --alert \
           -v --version \
           -h --help"
 
@@ -116,6 +117,10 @@ _tio()
             COMPREPLY=( $(compgen -W "unix: inet: inet6:" -- ${cur}) )
             return 0
             ;;
+        -x | --hexadecimal)
+            COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
+            return 0
+            ;;
         -r | --response-wait)
             COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
             return 0
@@ -132,8 +137,8 @@ _tio()
             COMPREPLY=( $(compgen -W "RTS_ON_SEND RTS_AFTER_SEND RTS_DELAY_BEFORE_SEND RTS_DELAY_AFTER_SEND RX_DURING_TX"  -- ${cur}) )
             return 0
             ;;
-        -x | --hexadecimal)
-            COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
+        --alert)
+            COMPREPLY=( $(compgen -W "none bell blink"  -- ${cur}) )
             return 0
             ;;
         -v | --version)