Handling arrays in WP_Query?

Thanks for an interesting plugin, the code looks great!

Would it be possible to fix WP_Query parameters that accept arrays?

For example:

[wqs post_type="post" post__in="206"][/wqs]

This results in WP_Query:

[post__in] => 206 (string)

Although it should be:

[post__in] => array(206)

Also then, this example:

[wqs post_type="post" post__in="206,123,456"][/wqs]

Should resolve to:

[post__in] => array(206,123,456)

There are also some other parameters that take arrays.

http://codex.wordpress.org/Class_Reference/WP_Query

https://wordpress.org/plugins/wpquery-shortcode/