[2.1] Added the support of Apache's passwords

[ezimuel]

Added the support of Apache's passwords in Zend\Crypt\Password\Apache.
I implemented the different password formats supported by htpasswd, reported here:
http://httpd.apache.org/docs/2.2/misc/password_encryptions.html

[weierophinney]

I think this can be cleaned up a bit. I'd do the following:

if (empty($options)) {
    return;
}
if (!is_array($options) && !$options instanceof Traversable) {
    throw new Exception\InvalidArgumentException(/* must be array or traversable */);
}
foreach ($options as $key => $value) {
    // set options as above
}

This way, the bulk of the work is not in a conditional, and you're not needing to cast Traversables to an array (as you're simply iterating over them).

[ezimuel]

OK

[weierophinney]

Looks good, @ezimuel -- make the changes as suggested, and I can merge.