Add '-c, --color' option

Allow user to select which ANSI color code to use to colorize the tio
text. To successfully set the color the color code must be in the range
0..255.

If color code is negative tio will print all available ANSI colors.

The default color is changed to bold white to make tio defaults usable
for most users, including color blind users.

src/bash-completion/tio.in

@@ -22,6 +22,7 @@ _tio()
           -v --version \
           -t --timestamp \
           -L --list-devices \
+          -c --color \
           -h --help"
 
     #  Complete the arguments to the options.
@@ -75,6 +76,10 @@ _tio()
             COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
             return 0
             ;;
+        -c | --color)
+            COMPREPLY=( $(compgen -W "$(seq 0 255)" -- ${cur}) )
+            return 0
+            ;;
         -v | --version)
             COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
             return 0