Add the ability to recognise the ACTION CTCP command

Hi there,

This is a simple one-line fix to add support for the ACTION CTCP command.

Tested this using the following code:
```php
<?php
require 'src/Phergie/Irc/ParserInterface.php';
require 'src/Phergie/Irc/Parser.php';

$parser = new \Phergie\Irc\Parser();
print_r($parser->parse(":henri!~hwatson@henriwatson.com PRIVMSG #test :".chr(01)."ACTION test".chr(01)."\r\n"));
```

Which should output the following:
```
Array
(
    [prefix] => :henri!~hwatson@henriwatson.com
    [nick] => henri
    [user] => ~hwatson@henriwatson.com
    [command] => PRIVMSG
    [params] => Array
        (
            [all] => #test :ACTION test
            [receivers] => #test
            [text] => ACTION test
        )

    [message] => :henri!~hwatson@henriwatson.com PRIVMSG #test :ACTION test

    [targets] => Array
        (
            [0] => #test
        )

    [ctcp] => Array
        (
            [command] => ACTION
            [params] => Array
                (
                    [all] => test
                )

        )

)
```


Thanks!